Antibody-drug conjugate produced by binding through linker having hydrophilic structure

ABSTRACT

As an antitumor drug which is excellent in terms of antitumor effect and safety, there is provided an antibody-drug conjugate in which an antitumor compound represented by the following formula (I) is conjugated to an antibody via a linker having a structure represented by the following formula: -L 1 -L 2 -L P -NH—(CH 2 )n 1 -L a -L b -L c - or -L 1 -L 2 -L P - wherein the antibody is connected to the terminal of L 1 , the antitumor compound is connected to the terminal of L c  or L P , and any one or two or more of linkers of L 1 , L 2 , and L P  has a hydrophilic structure.

TECHNICAL FIELD

The present invention relates to an antibody-drug conjugate having anantitumor compound conjugated to an antibody capable of targeting tumorcells via a linker structure moiety having a hydrophilic structure, theconjugate being useful as an antitumor drug.

BACKGROUND ART

An antibody-drug conjugate (ADC) having a drug with cytotoxicityconjugated to an antibody, whose antigen is expressed on a surface ofcancer cells and which also binds to an antigen capable of cellularinternalization, and therefore can deliver the drug selectively tocancer cells and is thus expected to cause accumulation of the drugwithin cancer cells and to kill the cancer cells (see, Non PatentLiteratures 1 to 3). As an ADC, Mylotarg (Gemtuzumab ozogamicin) inwhich calicheamicin is conjugated to an anti-CD33 antibody is approvedas a therapeutic agent for acute myeloid leukemia. Further, Adcetris(Brentuximab vedotin), in which auristatin E is conjugated to ananti-CD30 antibody, has recently been approved as a therapeutic agentfor Hodgkin's lymphoma and anaplastic large cell lymphoma (see, NonPatent Literature 4). The drugs contained in ADCs which have beenapproved until now target DNA or tubulin.

With regard to an antitumor, low-molecular-weight compounds,camptothecin derivatives, compounds that inhibit topoisomerase I toexhibit an antitumor effect, are known. Among them, an antitumorcompound represented by the formula below

(exatecan, chemical name:(1S,9S)-1-amino-9-ethyl-5-fluoro-2,3-dihydro-9-hydroxy-4-methyl-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-10,13(9H,15H)-dione)is a water soluble derivative of camptothecin (Patent Literature 1 and2). Unlike irinotecan currently used in clinical settings, an activationby an enzyme is unnecessary. Further, the inhibitory activity ontopoisomerase I is higher than SN-38 which is a main pharmaceuticallyactive substance of irinotecan and topotecan also used in clinicalsettings, and higher in vitro cytocidal activity is yielded for againstvarious cancer cells. In particular, it exhibits the effect againstcancer cells which have resistance to SN-38 or the like due toexpression of P-glycoprotein. Further, in a human tumor subcutaneouslytransplanted mouse model, it exhibited a potent antitumor effect, andthus has undergone the clinical studies, but has not been put on themarket yet (see, Non Patent Literatures 5 to 10). However, it remainsunclear whether or not exatecan functions effectively as an ADC.

DE-310 is a complex in which exatecan is conjugated to a biodegradablecarboxymethyldextran polyalcohol polymer via a GGFG peptide spacer(Patent Literature 3). By converting exatecan into a form of a polymerprodrug, so that a high blood retention property can be maintained andalso a high targetable property to a tumor area is passively increasedby utilizing the increased permeability of newly formed blood vesselswithin tumor and retention property in tumor tissues. With DE-310,through a cleavage of the peptide spacer by enzyme, exatecan andexatecan with glycine connected to an amino group are continuouslyreleased as a main active substance. As a result, the pharmacokineticsare improved and DE-310 was found to have higher effectiveness thanexatecan administered alone even though the dosage of exatecan is lowerthan the case of administration of exatecan alone according to varioustumor evaluation models in non-clinical studies. A clinical study wasconducted for DE-310, and effective cases were confirmed in humans, inwhich a report suggesting that the main active substance accumulates ina tumor than in normal tissues was present, however, there is also areport indicating that the accumulation of DE-310 and the main activesubstance in a tumor is not much different from the accumulation innormal tissues in humans, and thus no passive targeting is observed inhumans (see, Non Patent Literatures 11 to 14). As a result, DE-310 wasnot also commercialized, and it remains unclear whether or not exatecaneffectively functions as a drug oriented for such targeting.

As a compound relating to DE-310, a complex in which —NH(CH₂)₄C(═O)— isinserted between -GGFG-spacer and exatecan to form -GGFG-NH(CH₂)₄C(═O)—spacer structure is also known (Patent Literature 4). However, theantitumor effect of the complex is not known at all.

CITATION LIST Patent Literature

-   [Patent Literature 1] Japanese Patent Laid-Open No. 5-59061-   [Patent Literature 2] Japanese Patent Laid-Open No. 8-337584-   [Patent Literature 3] International Publication No. WO 1997/46260-   [Patent Literature 4] International Publication No. WO 2000/25825

Non Patent Literature

-   [Non Patent Literature 1] Ducry, L., et al. Bioconjugate    Chem. (2010) 21, 5-13.; Antibody-Drug Conjugates: Linking cytotoxic    payloads to monoclonal antibodies.-   [Non Patent Literature 2] Alley, S. C., et al. Current Opinion in    Chemical Biology (2010) 14, 529-537.; Antibody-drug conjugates:    targeted drug delivery for cancer.-   [Non Patent Literature 3] Damle N. K. Expert Opin. Biol.    Ther. (2004) 4, 1445-1452.; Tumour-targeted chemotherapy with    immunoconjugates of calicheamicin.-   [Non Patent Literature 4] Senter P. D., et al. Nature    Biotechnology (2012) 30, 631-637.; The discovery and development of    brentuximab vedotin for use in relapsed Hodgkin lymphoma and    systemic anaplastic large cell lymphoma.-   [Non Patent Literature 5] Kumazawa, E., Tohgo, A., Exp. Opin.    Invest. Drugs (1998) 7, 625-632.; Antitumour activity of DX-8951f: a    new camptothecin derivative.-   [Non Patent Literature 6] Mitsui, I., Kumazawa, E., Hirota, Y., et    al. Jpn J. Cancer Res. (1995) 86, 776-786.; A new water-soluble    camptothecin derivative, DX-8951f, exhibits potent antitumor    activity against human tumors in vitro and in vivo.-   [Non Patent Literature 7] Takiguchi, S., Tohgo, A., et al. Jpn J.    Cancer Res. (1997) 88, 760-769.; Antitumor effect of DX-8951, a    novel camptothecin analog, on human pancreatic tumor cells and their    CPT-11-resistant variants cultured in vitro and xenografted into    nude mice.-   [Non Patent Literature 8] Joto, N. et al. Int J Cancer (1997) 72,    680-686.; DX-8951f, a water-soluble camptothecin analog, exhibits    potent antitumor activity against a human lung cancer cell line and    its SN-38-resistant variant.-   [Non Patent Literature 9] Kumazawa, E. et al. Cancer Chemother.    Pharmacol. (1998) 42, 210-220.; Potent and broad antitumor effects    of DX-8951f, a water-soluble camptothecin derivative, against    various human tumors xenografted in nude mice.-   [Non Patent Literature 10] De Jager, R., et al. Ann N Y Acad    Sci (2000) 922, 260-273.; DX-8951f: summary of phase I clinical    trials.-   [Non Patent Literature 11] Inoue, K. et al. Polymer Drugs in the    Clinical Stage, Edited by Maeda et al. (2003), 145-153.;    CM-dextran-polyalcohol-camptothecin conjugate, DE-310 with a novel    carrier system and its preclinical data.-   [Non Patent Literature 12] Kumazawa, E. et al. Cancer Sci (2004) 95,    168-175.; DE-310, a novel macromolecular carrier system for the    camptothecin analog DX-8951f: Potent antitumor activities in various    murine tumor models.-   [Non Patent Literature 13] Soepenberg, O. et al. Clinical Cancer    Research, (2005) 11, 703-711.; Phase I and pharmacokinetic study of    DE-310 in Patients with Advanced Solid Tumors.-   [Non Patent Literature 14] Wente M. N. et al. Investigational New    Drugs (2005) 23, 339-347.; DE-310, a macromolecular prodrug of the    topoisomerase-I-inhibitor exatecan (DX-8951), in patients with    operable solid tumors.

SUMMARY OF INVENTION Technical Problem

With regard to the treatment of tumor by an antibody, an insufficientantitumor effect may be observed even when the antibody recognizes anantigen and binds to tumor cells, and there is a case in which a moreeffective antitumor antibody is needed. Further, many antitumorlow-molecular-weight compounds have a problem in safety like side effectand toxicity even the compounds have an excellent antitumor effect, itremains as a subject to achieve a superior therapeutic effect by furtherenhancing the safety. Thus, an object of the present invention is toyield to provide an antitumor drug having an excellent therapeuticeffect, which is excellent in terms of antitumor effect and safety.

Means to Solve the Problem

The inventors thought that, when an antitumor compound exatecan isconverted into an antibody-drug conjugate, via a linker, by conjugationto the antibody, which is capable of targeting tumor cells, that ishaving a property of recognizing tumor cells, a property of binding totumor cells, a property of internalizing within tumor cells, a cytocidalactivity against tumor cells, or the like, the antitumor compound can bemore surely delivered to tumor cells to specifically exhibit theantitumor effect of the compound in tumor cells, and thus the antitumoreffect can be surely exhibited and also an enhanced cytocidal effect ofthe antibody is expected, and a dose of the antitumor compound can bereduced compared to a case of administering the compound alone, and thusan influence of the antitumor compound on normal cells can be alleviatedso that higher safety can be achieved.

In this connection, the inventors created a linker with a specificstructure.

The present inventors have particularly constructed a linker having:

a linker structure in which a hydrophilic amino acid other than glycinis connected at the N terminal of a peptide moiety of the linker;a linker structure in which glycine or glycylglycine is connected at theC terminal of a peptide moiety of the linker; ora linker structure in which a linker element having a hydrophilicstructure is inserted between a peptide moiety in the linker and anantibody;and successfully obtained an antibody-drug conjugate having exatecanconjugated to an antibody via such a linker. The present inventors havefurther found that this antibody-drug conjugate is excellent in therelease of the drug component having an antitumor effect, and as aresult, the antibody-drug conjugate of the present invention exerts anexcellent antitumor effect, leading to the completion of the presentinvention.

Specifically, the present invention relates to the followings.

[1] An antibody-drug conjugate wherein an antitumor compound representedby the following formula:

is conjugated to an antibody via a linker having a structure representedby the following formula:

-   -L¹-L²-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- or -L¹-L²-L^(P)-.

Here, the antibody is connected to the terminal of L¹, the antitumorcompound is connected to the terminal of L^(c) or L^(P),

whereinn¹ represents an integer of 0 to 6,L¹ represents -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)—,-(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—,—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—,—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-, or —C(═O)—(CH₂)n⁵-C(═O)—,

wherein n² represents an integer of 2 to 8, n³ represents an integer of1 to 8, n⁴ represents an integer of 1 to 8, n⁵ represents an integer of1 to 8,

L² represents —NH—(CH₂—CH₂—O) n⁶-CH₂—CH₂—C(═O)—,—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)—, —S—(CH₂)n⁸-C(═O)—, or a singlebond,

wherein n⁶ represents an integer of 0 to 6, n⁷ represents an integer of1 to 4, n⁸ represents an integer of 1 to 6,

L^(P) represents a peptide residue consisting of 3 to 8 amino acids,L^(a) represents —C(═O)—NH—, —NR¹—(CH₂)n⁹-, —O—, or a single bond,

wherein n⁹ represents an integer of 1 to 6, R¹ represents a hydrogenatom, an alkyl group having 1 to 6 carbon atoms, —(CH₂)n^(a)-COOH, or—(CH₂)n^(b)-OH, n^(a) represents an integer of 1 to 4, n^(b) representsan integer of 1 to 6, L^(b) represents —CR²(—R³)—, —O—, —NR⁴—, or asingle bond,

wherein R² and R³ each independently represent a hydrogen atom, an alkylgroup having 1 to 6 carbon atoms, —(CH₂)n^(c)-NH₂, —(CH₂)n^(d)-COOH, or—(CH₂)n^(e)-OH, R⁴ represents a hydrogen atom or an alkyl group having 1to 6 carbon atoms, n^(c) represents an integer of 0 to 6, n^(d)represents an integer of 1 to 4, n^(e) represents an integer of 1 to 4,provided that when n^(c) is 0, R² and R³ are not the same as each other,

L^(c) represents —CH₂— or —C(═O)—,

-   -(Succinimid-3-yl-N)— has a structure represented by the following    formula:

which is connected to the antibody at position 3 thereof and isconnected to a methylene group in the linker structure containing thisstructure on the nitrogen atom at position 1,—(N-ly-3-diminiccuS)- has a structure represented by the followingformula:

which is connected to L² at position 3 thereof and is connected to amethylene group in the linker structure containing this structure on thenitrogen atom at position 1,

-   cyc.Hex(1,4) represents a 1,4-cyclohexylene group, and when L² is    —S—(CH₂)n⁸-C(═O)—, L¹ is    —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-.    provided that any one or two or more of linkers of L¹, L², and L^(P)    have a structure containing a hydrophilic structure, and    said hydrophilic structure means,    as for linker L^(P), the case in which,    L^(P) is a peptide residue having a hydrophilic amino acid other    than glycin at the N terminal, or    L^(P) is a peptide residue in which the C terminal is an    oligopeptide consisting of 2 or 3 or more glycines and is connected    to the antitumor compound, and even in case that a hydrophilic amino    acid is present at N terminal, no other hydrophilic amino acid than    glycine is present thereat, or    as for linker L¹, the case in which L¹ is    -(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—, or    as for linker L², the case in which L² is —N[—(CH₂CH₂—O)    n⁷-CH₂CH₂—OH]-CH₂—C(═O)—.

The present invention also relates to each of the followings.

[2] The antibody-drug conjugate according to [1], wherein

-   L¹ is -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)—,    -(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—, or    —CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—,

wherein n² represents an integer of 2 to 8, n³ represents an integer of1 to 8, n⁴ represents an integer of 1 to 8,

-   L² is —NH—(CH₂—CH₂—O) n⁶-CH₂—CH₂—C(═O)—, —N[—(CH₂CH₂—O)    n⁷-CH₂CH₂—OH]-CH₂—C(═O)—, or a single bond,

wherein n⁶ represents an integer of 0 to 6, n⁷ represents an integer of1 to 4,

L^(P) is a peptide residue consisting of 3 to 8 amino acids, each ofL^(a) and L^(b) is a single bond, and

L^(c) is —C(═O).

[3] The antibody-drug conjugate according to [1] or [2], wherein any oneof linkers of L¹, L², and L^(P) is the linker containing the hydrophilicstructure.[4] The antibody-drug conjugate according to [3], wherein the linkercontaining the hydrophilic structure is L^(P).[5] The antibody-drug conjugate according to [4], wherein L^(P) is apeptide residue having a hydrophilic amino acid other than glycin at theN terminal.[6] The antibody-drug conjugate according to [5], wherein thehydrophilic amino acid other than glycin is aspartic acid, glutamicacid, lysine, serine, threonine, glutamine, asparagine, histidine,tyrosine, or arginine.[7] The antibody-drug conjugate according to [5], wherein the N-terminalhydrophilic amino acid other than glycin in L^(P) is glutamic acid,aspartic acid, or lysine.[8] The antibody-drug conjugate according to [6] or [7], wherein apeptide residue following the N-terminal hydrophilic amino acid in L^(P)is amino acid residue consisting of amino acids selected fromphenylalanine, glycine, valine, lysine, citrulline, serine, glutamicacid, and aspartic acid.[9] The antibody-drug conjugate according to [8], wherein a peptideresidue following the N-terminal hydrophilic amino acid in L^(P) is apeptide residue consisting of 3 or 4 amino acids.[10] The antibody-drug conjugate according to [9], wherein the peptideresidue following the N-terminal hydrophilic amino acid in L^(P) is GGFor GGFG.[11] The antibody-drug conjugate according to any one of [5] to [10],wherein L^(P) is DGGF, KGGF, EGGF, DGGFG, KGGFG, or EGGFG.[12] The antibody-drug conjugate according to any one of [5] to [10],wherein L^(P) is DGGFG, KGGFG, or EGGFG.[13] The antibody-drug conjugate according to any one of [1] to [12],wherein the linker is a linker having a structure represented by-L¹-L²-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-.[14] The antibody-drug conjugate according to [13], wherein L^(c) is—C(═O)—.[15] The antibody-drug conjugate according to [14], wherein L¹ is-(Succinimid-3-yl-N)—(CH₂)n²-C(═O)—, n² is an integer of 2 to 5, and L²is a single bond.[16] The antibody-drug conjugate according to [15], wherein n² is 5.[17] The antibody-drug conjugate according to [15] or [16], wherein n¹is 1 to 3.[18] The antibody-drug conjugate according to any one of [5] to [17],wherein the structure of the —NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- moiety inthe linker is

-   —NH—CH₂—C(═O)—,-   —NH—(CH₂)₂—C(═O)—,-   —NH—(CH₂)₃—C(═O)—,-   —NH—CH₂—O—CH₂—C(═O)—, or-   —NH—(CH₂)₂—O—CH₂—C(═O)—.    [19] The antibody-drug conjugate according to any one of [5] to    [17], wherein the structure of the —NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-    moiety in the linker is-   —NH—CH₂—C(═O)—,-   —NH—(CH₂)₂—C(═O)—, or-   —NH—(CH₂)₃—C(═O)—.    [20] The antibody-drug conjugate according to any one of [1] to    [12], wherein the linker is a linker having a structure represented    by -L¹-L²-L^(P)-.    [21] The antibody-drug conjugate according to [20], wherein L¹ is    -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)—, n² is an integer of 2 to 5, and    L² is a single bond.    [22] The antibody-drug conjugate according to [21], wherein n² is 5.    [23] The antibody-drug conjugate according to [4], wherein L^(P) is    a peptide residue in which the C terminal is an oligopeptide    consisting of 2 or 3 or more glycines and is connected to the    antitumor compound, and the N terminal is not a hydrophilic amino    acid other than glycin, even in case that a hydrophilic amino acid    is present at N terminal.    [24] The antibody-drug conjugate according to [23], wherein the    peptide residue is a linker consists of 4 to 8 amino acids.    [25] The antibody-drug conjugate according to [23], wherein the    C-terminal glycine oligopeptide is an oligopeptide consisting of 2    or 3 glycines.    [26] The antibody-drug conjugate according to any one of [23] to    [25], wherein the peptide residue of the linker is GGFGG or GGFGGG.    [27] The antibody-drug conjugate according to any one of [23] to    [26], wherein L¹ is -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)—, and n² is    an integer of 2 to 5.    [28] The antibody-drug conjugate according to [27], wherein n² is 5.    [29] The antibody-drug conjugate according to [3], wherein L¹ is    -(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—.    [30] The antibody-drug conjugate according to [29], wherein n³ is 2    or 3.    [31] The antibody-drug conjugate according to [3], wherein L² is    —N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)—.    [32] The antibody-drug conjugate according to [31], wherein n⁷ is 2    to 4.    [33] The antibody-drug conjugate according to any one of [29] to    [32], wherein the linker is a linker having a structure represented    by -L¹-L²-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-.    [34] The antibody-drug conjugate according to [33], wherein L^(c) is    —C(═O)—.    [35] The antibody-drug conjugate according to any one of [29] to    [34], wherein n¹ is 1 to 3.    [36] The antibody-drug conjugate according to any one of [29] to    [35], wherein L^(P) is GGFG.    [37] The antibody-drug conjugate according to any one of [29] to    [36], wherein the structure of the —NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-    moiety in the linker is-   —NH—CH₂—C(═O)—,-   —NH—(CH₂)₂—C(═O)—,-   —NH—(CH₂)₃—C(═O)—,-   —NH—CH₂—O—CH₂—C(═O)—, or-   —NH—(CH₂)₂—O—CH₂—C(═O)—.    [38] The antibody-drug conjugate according to any one of [29] to    [36], wherein the structure of the —NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-    moiety in the linker is-   —NH—CH₂—C(═O)—,-   —NH—(CH₂)₂—C(═O)—, or-   —NH—(CH₂)₃—C(═O)—.    [39] The antibody-drug conjugate according to any one of [1] to    [38], wherein the bond between the antibody and L¹ is    a thioether bond which is formed at a disulfide bond moiety present    in a hinge part of the antibody,    a disulfide bond which is formed at a disulfide bond moiety present    in a hinge part of the antibody, or an amide bond which is formed at    an amino group present on a side chain of an amino acid constituting    the antibody or at the terminal amino group.    [40] The antibody-drug conjugate according to any one of [1] to    [38], wherein the bond between the antibody and L¹ is    a thioether bond which is formed at a disulfide bond moiety present    in a hinge part of the antibody, or an amide bond which is formed at    an amino group present on a side chain of an amino acid constituting    the antibody or at the terminal amino group.    [41] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is one structure selected from the following group:-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF—NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGF—NH—CH₂—O—CH₂—C(═O)-(NH-DX),-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX),-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX),-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX),-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)₁-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)₁-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF-NH—CH₂—O—CH₂—C(═O)-(NH-DX),-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX),-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX),-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX),-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX),-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂CH₂—C(═O)-(NH-DX),-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGF-NH—CH₂—O—CH₂—C(═O)-(NH-DX),-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX),-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX),-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-KGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX),-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX),-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGF-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGF-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX).    [42] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is one structure selected from the following group:-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF—NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX).    [43] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is one structure selected from the following group:-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGF—NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX).    [44] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is one structure selected from the following group:-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX).    [45] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is one structure selected from the following group:-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—(NH-DX),-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF—(NH-DX),-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-(NH-DX),-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-(NH-DX).    [46] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is any of the following structures:-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-(NH-DX),-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-(NH-DX).    [47] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is the following structure:-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-(NH-DX).    [48] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is one structure selected from the following group:-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF—(NH-DX),-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGF—(NH-DX),-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-(NH-DX),-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGFG-(NH-DX).    [49] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is any of the following structures:-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-(NH-DX),-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGFG-(NH-DX).    [50] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is the following structure:-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-(NH-DX).    [51] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is one structure selected from the following group:-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGF—(NH-DX),-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGF—(NH-DX),-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-(NH-DX),-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGFG-(NH-DX).    [52] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is any of the following structures:-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-(NH-DX),-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGFG-(NH-DX).    [53] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is the following structure:-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-(NH-DX).    [54] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is one structure selected from the following group:-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—(NH-DX),-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF—(NH-DX),-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-(NH-DX),-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-(NH-DX).    [55] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is one structure selected from the following group:-   -(Succinimid-3-yl-N)—CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)—(NH-DX),-   -(Succinimid-3-yl-N)—CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   -(Succinimid-3-yl-N)—CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   -(Succinimid-3-yl-N)—CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX).    [56] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is any of the following structures:-   -(Succinimid-3-yl-N)—CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)—(NH-DX),-   -(Succinimid-3-yl-N)—CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX).    [57] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is the following structure:-   -(Succinimid-3-yl-N)—CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-(NH-DX).    [58] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is one structure selected from the following group:-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)—(NH-DX),-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX).    [59] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is the following structure:-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-(NH-DX).    [60] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is one structure selected from the following group:-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)—(NH-DX),-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX).    [61] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is the following structure:-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-(NH-DX),    [62] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is one structure selected from the following group:-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)-(NH-DX),-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX),-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX).    [63] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is the following structure:-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-(NH-DX).    [64] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is any of the following structures:-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-GGFGG-(NH-DX),-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-GGFGGG-(NH-DX).    [65] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is any of the following structures:-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-GGFGG-(NH-DX),-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-GGFGGG-(NH-DX).    [66] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is any of the following structures:-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-GGFGG-(NH-DX),-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-GGFGGG-(NH-DX).    [67] The antibody-drug conjugate according to [1], [2], [39], or    [40], wherein the drug-linker structure moiety in the antibody-drug    conjugate is any of the following structures:-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-GGFGG-(NH-DX),-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-GGFGGG-(NH-DX).

Here, according to any one of [41] to [67], -(Succinimid-3-yl-N)— has astructure represented by the following formula:

which is connected to the antibody at position 3 thereof and isconnected to a methylene group in the linker structure containing thisstructure on the nitrogen atom at position 1,cyc.Hex(1,4) represents a 1,4-cyclohexylene group,—(N-ly-3-diminiccuS)- has a structure represented by the followingformula:

which is connected to L² at position 3 thereof and is connected to amethylene group in the linker structure containing this structure on thenitrogen atom at position 1, and—(NH-DX) is a group represented by the following formula:

wherein the nitrogen atom of the amino group at position 1 is theconnecting position.[68] The antibody-drug conjugate according to any one of [1] to [67],wherein an average number of conjugated antitumor compounds per antibodyis in a range of from 1 to 10.[69] The antibody-drug conjugate according to any one of [1] to [67],wherein an average number of conjugated antitumor compounds per antibodyis in a range of from 1 to 8.[70] The antibody-drug conjugate according to any one of [1] to [67],wherein an average number of conjugated antitumor compounds per antibodyis in a range of from 3 to 8.[71] The antibody-drug conjugate according to any one of [1] to [70],wherein the antibody is an antibody having one or more of a property ofrecognizing a target cell, a property of binding to a target cell, aproperty of internalizing in a target cell, and a property of damaging atarget cell.[72] The antibody-drug conjugate according to [71], wherein the targetcell is a tumor cell.[73] The antibody-drug conjugate according to any one of [1] to [72],wherein the antibody is an anti-A33 antibody, an anti-B7-H3 antibody, ananti-CanAg antibody, an anti-CD20 antibody, an anti-CD22 antibody, ananti-CD30 antibody, an anti-CD33 antibody, an anti-CD56 antibody, ananti-CD70 antibody, an anti-CEA antibody, an anti-Cripto antibody, ananti-EphA2 antibody, an anti-G250 antibody, an anti-MUC1 antibody, ananti-GPNMB antibody, an anti-integrin antibody, an anti-PSMA antibody,an anti-tenascin-C antibody, an anti-SLC44A4 antibody, or ananti-mesothelin antibody.[74] The antibody-drug conjugate according to any one of [1] to [72],wherein the antibody is an anti-B7-H3 antibody, an anti-CD30 antibody,an anti-CD33 antibody, or an anti-CD70 antibody.[75] The antibody-drug conjugate according to any one of [1] to [72],wherein the antibody is an anti-B7-H3 antibody.[76] A drug containing the antibody-drug conjugate according to any oneof [1] to [75], a salt thereof or a hydrate thereof.[77] An antitumor drug and/or anticancer drug containing theantibody-drug conjugate according to any one of [1] to [75], a saltthereof or a hydrate thereof.[78] The antitumor drug and/or anticancer drug according to [77], whichis applied to lung cancer, kidney cancer, urothelial cancer, colorectalcancer, prostate cancer, glioblastoma multiforme, ovarian cancer,pancreatic cancer, breast cancer, melanoma, liver cancer, bladdercancer, stomach cancer, or esophageal cancer.[79] A pharmaceutical composition containing the antibody-drug conjugateaccording to any one of [1] to [75], a salt thereof or a hydrate thereofas an active component, and a pharmaceutically acceptable formulationcomponent.[80] The pharmaceutical composition according to [79], which is appliedto lung cancer, kidney cancer, urothelial cancer, colorectal cancer,prostate cancer, glioblastoma multiforme, ovarian cancer, pancreaticcancer, breast cancer, melanoma, liver cancer, bladder cancer, stomachcancer, or esophageal cancer.[81] A method for treating tumor and/or cancer comprising administeringthe antibody-drug conjugate according to any one of [1] to [75], a saltthereof or a hydrate thereof.[82] The pharmaceutical composition according to [81], which is appliedto lung cancer, kidney cancer, urothelial cancer, colorectal cancer,prostate cancer, glioblastoma multiforme, ovarian cancer, pancreaticcancer, breast cancer, melanoma, liver cancer, bladder cancer, stomachcancer, or esophageal cancer.[83] An antibody-drug conjugate wherein an antitumor compoundrepresented by the following formula:

is conjugated to an antibody via a linker having a structure representedby the following formula:

-   -L¹-L²-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- or -L¹-L²-L^(P)-.

Here, the antibody is connected to the terminal of L¹, the antitumorcompound is connected to the terminal of L^(c) or L^(P),

whereinn¹ represents an integer of 0 to 6,L¹ represents -(Succinimid-3-yl-N)—(CH₂)n⁴-C(═O)—,-(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—, or—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—,

wherein n² represents an integer of 2 to 8, n³ represents an integer of1 to 8, n⁴ represents an integer of 1 to 8,

L² represents —NH—(CH₂—CH₂—O) n⁶-CH₂—CH₂—C(═O)—, —N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)—, or a single bond,

wherein n⁶ represents an integer of 0 to 6, n⁷ represents an integer of1 to 4,

L^(P) represents a peptide residue consisting of 3 to 8 amino acids,L^(a) represents —O— or a single bond,L^(b) represents CR²(—R³)— or a single bond,

wherein R² and R³ each independently represent a hydrogen atom,

L^(c) represents —C(═O)—,

-   -(Succinimid-3-yl-N)— has a structure represented by the following    formula:

which is connected to the antibody at position 3 thereof and isconnected to a methylene group in the linker structure containing thisstructure on the nitrogen atom at position 1,provided that any one or two or more of linkers of L¹, L², and L^(P)have a structure containing a hydrophilic structure,said hydrophilic structure means,as for linker L^(P), the case in which,L^(P) is a peptide residue having a hydrophilic amino acid other thanglycine at the N terminal, orL^(P) is a peptide residue in which the C terminal is an oligopeptideconsisting of 2 or 3 or more glycines and is connected to the antitumorcompound, and even in case that a hydrophilic amino acid is present at Nterminal, no other hydrophilic amino acid than glycine is presentthereat, oras for linker L¹, in case that L¹ is-(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—, oras for linker L², in case that L² is —N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)—.[84] An antibody-drug conjugate wherein an antitumor compoundrepresented by the following formula:

is conjugated to an antibody via a linker having a structure representedby the following formula:

-   -L¹-L²-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- or -L¹-L²-L^(P)-.

Here, the antibody is connected to the terminal of L¹, the antitumorcompound is connected to the terminal of L^(c) or L^(P) with thenitrogen atom of the amino group at position 1 as the connectingposition,

whereinn¹ represents an integer of 0 to 6,L¹ represents -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)— or-(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)— and is connected to theantibody via a thioether bond at a disulfide bond moiety in a hinge partof the antibody,

wherein n² represents an integer of 2 to 8, n³ represents an integer of1 to 8,

L² represents —N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)— or a single bond,

wherein n⁷ represents an integer of 1 to 4,

L^(P) represents a peptide residue consisting of 3 to 8 amino acids,L^(a) represents a single bond,L^(b) represents a single bond,L^(c) represents —C(═O)—,

-   -(Succinimid-3-yl-N)— has a structure represented by the following    formula:

which is connected to the antibody at position 3 thereof and isconnected to a methylene group in the linker structure containing thisstructure on the nitrogen atom at position 1,provided that any one or two or more of linkers of L¹, L², and L^(P)have a structure containing a hydrophilic structure, andsaid hydrophilic structure means,as for linker L^(P), the case in which,L^(P) is a peptide residue having a hydrophilic amino acid other thanglycine at the N terminal, orL^(P) is a peptide residue in which the C terminal is an oligopeptideconsisting of 2 or 3 or more glycines and is connected to the antitumorcompound, and even in case that a hydrophilic amino acid is present at Nterminal, no other hydrophilic amino acid than glycine is presentthereat, oras for linker L¹, the case in which L¹ is-(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—, oras for linker L², the case in which L² is—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)—.[85] A drug-linker intermediate compound represented by the followingformula:

-   Q-L^(1a)(CH₂)n^(Q)-C(═O)-L^(2a)-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX),    or-   Q-L^(1a)-(CH₂)n^(Q)-C(═O)-L^(2a)-L^(P)-(NH-DX).

In the formula, Q represents (maleimid-N-yl)-, HS—, X—CH₂—C(═O)—NH—, or(Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—, X represents a bromine atom or aniodine atom,

L^(1a) represents —CH[—(CH₂)n³-COOH]- or a single bond,n^(Q) represents an integer of 0 to 8,L^(2a) represents —NH—(CH₂—CH₂—O) n⁶-CH₂—CH₂—C(═O)—,—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)—, or a single bond,

wherein n⁶ represents an integer of 0 to 6, n⁷ represents an integer of1 to 4,

L^(P) represents a peptide residue consisting of 3 to 8 amino acids,n¹ represents an integer of 0 to 6,L^(a) represents —C(═O)—NH—, —NR¹—(CH₂)n⁹-, —O—, or a single bond,

wherein n⁹ represents an integer of 1 to 6, R¹ represents a hydrogenatom, an alkyl group having 1 to 6 carbon atoms, —(CH₂)n^(a)-COOH, or—(CH₂)n^(b)-OH, n^(a) represents an integer of 1 to 4, n^(b) representsan integer of 1 to 6, L^(b) represents —CR²(—R³)—, —O—, —NR⁴—, or asingle bond,

wherein R² and R³ each independently represent a hydrogen atom, an alkylgroup having 1 to 6 carbon atoms, —(CH₂)n^(c)-NH₂, —(CH₂)n^(d-)COOH, or—(CH₂)n^(e)-OH, R⁴ represents a hydrogen atom or an alkyl group having 1to 6 carbon atoms, n^(c) represents an integer of 0 to 6, n^(d)represents an integer of 1 to 4, n^(e) represents an integer of 1 to 4,provided that when n^(c) is 0, R² and R³ are not the same as each other,

L^(c) represents —CH₂— or —C(═O)—,In the above, (maleimid-N-yl)- is a group represented by the followingformula:

wherein the nitrogen atom is the connecting position,(Pyrrolidine-2,5-dione-N-yl) is a group represented by the followingformula:

wherein the nitrogen atom is the connecting position, and—(NH-DX) is a group represented by the following formula:

wherein the nitrogen atom of the amino group at position 1 is theconnecting position,provided that any one or two or more of linkers ofL^(1a)-(CH₂)n^(Q)-C(═O)—, L² and L^(P) have a structure containinghydrophilic structure,and said hydrophilic structure means,as for linker L^(P), the case in which,L^(P) is a peptide residue having a hydrophilic amino acid other thanglycin at the N terminal, orL^(P) is a peptide residue in which the C terminal is an oligopeptideconsisting of 2 or 3 or more glycines and is connected to the antitumorcompound, and even in case that a hydrophilic amino acid is present at Nterminal, no other hydrophilic amino acid than glycine is presentthereat, oras for linker L^(1a)-(CH₂)n^(Q)-C(═O)—, the case in whichL^(1a-)-(CH₂)n^(Q)-C(═O)— is —CH[—(CH₂)n³-COOH]—C(═O)—, oras for linker L^(2a), the case in which L^(3a) is —N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)—.[86] A drug-linker intermediate compound represented by the followingformula:

-   Q-L^(1a)-(CH₂)n^(Q)-C(═O)-L^(2a)-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX),    or-   Q-L^(1a)-(CH₂)n^(Q)-C(═O)-L^(2a)-L^(P)-(NH-DX),    wherein Q represents (maleimid-N-yl)-, HS—, X—CH₂—C(═O)—NH—, or    (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—,    X represents a bromine atom or an iodine atom,    L^(1a) represents —CH[—(CH₂)n³-COOH]- or a single bond,    n^(Q) represents an integer of 0 to 8,    L^(2a) represents —NH—(CH₂—CH₂—O) n⁶-CH₂—CH₂—C(═O)—,    —N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)—, or a single bond,

wherein n⁶ represents an integer of 0 to 6, n⁷ represents an integer of1 to 4,

L^(P) represents a peptide residue consisting of 3 to 8 amino acids,n¹ represents an integer of 0 to 6,L^(a) and L^(b) each independently represent a single bond,L^(c) represents —C(═O)—,(maleimid-N-yl)- is a group represented by the following formula:

wherein the nitrogen atom is the connecting position,(Pyrrolidine-2,5-dione-N-yl) is a group represented by the followingformula:

wherein the nitrogen atom is the connecting position, and—(NH-DX) is a group represented by the following formula:

wherein the nitrogen atom of the amino group at position 1 is theconnecting position.[87] The compound according to [86], which is selected from thefollowing group:

-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—C(═O)—(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂CH₂—C(═O)-(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF-NH—CH₂—O—CH₂—C(═O)-(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGF—NH—CH₂CH₂—C(═O)—(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂CH₂—C(═O)-(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF-NH—CH₂—O—CH₂—C(═O)-(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—C(═O)-(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)_(f)-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—C(═O)-(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX).    [88] The compound according to [86], which is selected from the    following group:-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—C(═O)—(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂CH₂—C(═O)-(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGF—NH—CH₂CH₂—C(═O)—(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂CH₂—C(═O)-(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—C(═O)-(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—C(═O)-(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX).    [89] The compound according to [86], which is selected from the    following group:-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂—C(═O)-(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF—NH—CH₂—O—CH₂—C(═O)-(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGF—NH—CH₂CH₂—C(═O)—(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-KGGF—NH—CH₂—O—CH₂—C(═O)-(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-KGGF—NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—C(═O)—(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—C(═O)—(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-KGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX).    [90] The compound according to [86], which is selected from the    following group:-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—C(═O)-(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)-(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-KGGF—NH—CH₂CH₂—C(═O)-(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂CH₂—C(═O)-(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—C(═O)-(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂—C(═O)-(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX).    [91] The compound according to [86], which is selected from the    following group:-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—C(═O)-(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF-NH—CH₂—O—CH₂—C(═O)-(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGF—NH—CH₂CH₂—C(═O)-(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF-NH—CH₂—O—CH₂—C(═O)-(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX).    [92] The compound according to [86], which is selected from the    following group:-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF—NH—CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX).-   [93] The compound according to [86], which is selected from the    following group:-   HS—CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂—C(═O)—(NH-DX),-   HS—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   HS—CH₂CH₂—C(═O)-DGGF-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   HS—CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),-   HS—CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂—C(═O)—(NH-DX),-   HS—CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   HS—CH₂CH₂—C(═O)—KGGF-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   HS—CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),-   HS—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—C(═O)—(NH-DX),-   HS—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   HS—CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   HS—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),-   HS—CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—C(═O)—(NH-DX),-   HS—CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   HS—CH₂CH₂—C(═O)—KGGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   HS—CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX).    [94] The compound according to [86], which is selected from the    following group:-   HS—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—C(═O)—(NH-DX),-   HS—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   HS—CH₂CH₂—C(═O)—KGGF—NH—CH₂CH₂—C(═O)—(NH-DX),-   HS—CH₂CH₂—C(═O)—KGGF—NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   HS—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—C(═O)—(NH-DX),-   HS—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   HS—CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—C(═O)—(NH-DX),-   HS—CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX).    [95] The compound according to [86], which is selected from the    following group:-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF—(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-(NH-DX).    [96] The compound according to [86], which is any of the followings:-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-GGFGG-(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-GGFGGG-(NH-DX).    [97] The compound according to [86], which is selected from the    following group:-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF—(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGF—(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGFG-(NH-DX).    [98] The compound according to [86], which is any of the followings:-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-GGFGG-(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-GGFGGG-(NH-DX).    [99] The compound according to [86], which is selected from the    following group:-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-(NH-DX).-   The compound according to [86], which is any of the followings:-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-GGFGG-(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-GGFGGG-(NH-DX).

The compound according to [86], which is selected from the followinggroup:

-   HS—CH₂CH₂—C(═O)-DGGF—(NH-DX),-   HS—CH₂CH₂—C(═O)—KGGF—(NH-DX),-   HS—CH₂CH₂—C(═O)-DGGFG-(NH-DX),-   HS—CH₂CH₂—C(═O)—KGGFG-(NH-DX).

The compound according to [86], which is selected from the followinggroup:

-   (maleimid-N-yl)-CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)—(NH-DX),-   (maleimid-N-yl)-CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   (maleimid-N-yl)-CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   (maleimid-N-yl)-CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX).

The compound according to [86], which has a structure of the followingformula:

-   (maleimid-N-yl)-CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-(NH-DX).

The compound according to [86], which is selected from the followinggroup:

-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH(CH₂CH₂—COOH)—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH(CH₂CH₂—COOH)—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH(CH₂CH₂—COOH)—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH(CH₂CH₂—COOH)—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX).

The compound according to [86], which is selected from the followinggroup:

-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)—(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX),-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX).

The compound according to [86], which is selected from the followinggroup:

-   X—CH₂—C(═O)—NH—CH₂CH—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)—(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX).

The compound according to [86], which is selected from the followinggroup:

-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX).

In the linker according to any one of [87] to [107], (maleimid-N-yl)- isa group represented by the following formula:

wherein the nitrogen atom is the connecting position, X represents ahalogen atom,(Pyrrolidine-2,5-dione-N-yl)- is a group represented by the followingformula:

wherein the nitrogen atom is the connecting position, and —(NH-DX) is agroup represented by the following formula:

wherein the nitrogen atom of the amino group at position 1 is theconnecting position.

A linker having a structure represented by the following formula:

-   -L¹-L²-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- or -L¹-L²-L^(P)-    for obtaining an antibody-drug conjugate in which a antitumor    compound is conjugated to an antibody via the linker.

In the above, the antibody is connected to the terminal of L¹, theantitumor compound is connected to the terminal of L^(c) or L^(P),

whereinn¹ represents an integer of 0 to 6,L¹ represents -(Succinimid-3-yl-N)—(CH₂)n⁴-C(═O)—,-(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—,—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—,—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-, or —C(═O)—(CH₂)n⁵-C(═O)—,

wherein n² represents an integer of 2 to 8, n³ represents an integer of1 to 8, n⁴ represents an integer of 1 to 8, n⁵ represents an integer of1 to 8,

L² represents —NH—(CH₂—CH₂—O) n⁶-CH₂—CH₂—C(═O)—,—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)—, —S—(CH₂)n⁸-C(═O)—, or a singlebond,

wherein n⁶ represents an integer of 0 to 6, n⁷ represents an integer of1 to 4, n⁸ represents an integer of 1 to 6,

L^(P) represents a peptide residue consisting of 3 to 8 amino acids,L^(a) represents —C(═O)—NH—, —NR¹—(CH₂)n⁹-, —O—, or a single bond,

wherein n⁹ represents an integer of 1 to 6, R¹ represents a hydrogenatom, an alkyl group having 1 to 6 carbon atoms, —(CH₂)n^(a)-COOH, or—(CH₂)n^(b)-OH, n^(a) represents an integer of 1 to 4, n^(b) representsan integer of 1 to 6, L^(b) represents —CR²(—R³)—, —O—, —NR⁴—, or asingle bond,

wherein R² and R³ each independently represent a hydrogen atom, an alkylgroup having 1 to 6 carbon atoms, —(CH₂)n^(c)-NH₂, —(CH₂)n^(d)-COOH, or—(CH₂)n^(e)-OH, R⁴ represents a hydrogen atom or an alkyl group having 1to 6 carbon atoms, n^(c) represents an integer of 0 to 6, n^(d)represents an integer of 1 to 4, n^(e) represents an integer of 1 to 4,provided that when n^(c) is 0, R² and R³ are not the same as each other,

L^(c) represents —CH₂— or —C(═O)—,

-   -(Succinimid-3-yl-N)— has a structure represented by the following    formula:

which is connected to the antibody at position 3 thereof and isconnected to a methylene group in the linker structure containing thisstructure on the nitrogen atom at position 1,—(N-ly-3-diminiccuS)- has a structure represented by the followingformula:

which is connected to L² at position 3 thereof and is connected to amethylene group in the linker structure containing this structure on thenitrogen atom at position 1,cyc.Hex(1,4) represents a 1,4-cyclohexylene group, and when L² is—S—(CH₂)n⁸-C(═O)—, L¹ is —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-.provided that any one or two or more of linkers of L¹, L², and L^(P)have a structure containing a hydrophilic structure,said hydrophilic structure means,as for linker L^(P), the case in which,L^(P) is a peptide residue having a hydrophilic amino acid other thanglycin at the N terminal, orL^(P) is a peptide residue in which the C terminal is an oligopeptideconsisting of 2 or 3 or more glycines and is connected to the antitumorcompound, and even in case that a hydrophilic amino acid is present at Nterminal, no other hydrophilic amino acid than glycine is presentthereat,as for linker L¹, the case in which L¹ is-(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—, oras for linker L², the case in which L² is —N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)—.

The linker according to [108], which is selected from the followinggroup, provided that the left terminal is a connecting position to theantibody and the right terminal is a connecting position to theantitumor compound:

-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)—,-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂—O—CH₂—C(═O)—,-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂—O—CH₂—C(═O)—,-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—,-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)—,-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—,-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGF—NH—CH₂CH₂CH₂—C(═O)—,-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGF—NH—CH₂—O—CH₂—C(═O)—,-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂—O—CH₂—C(═O)—,-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂CH₂—C(═O)—,-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGFG-NH—CH₂—O—CH₂—C(═O)—,-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—,-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂CH₂—C(═O)—,-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF-NH—CH₂—O—CH₂—C(═O)—,-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂—O—CH₂—C(═O)—,-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—,-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)—,-   —CH₂—C(═O)—NH—CH₂CH₂-C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—,-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂CH₂—C(═O)—,-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGF-NH—CH₂—O—CH₂—C(═O)—,-   —CH₂—C(═O)—NH—CH₂CH₂-C(═O)—KGGF-NH—CH₂CH₂—O—CH₂—C(═O)—,-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂CH₂—C(═O)—,-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGFG-NH—CH₂—O—CH₂—C(═O)—,-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—,-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂CH₂—C(═O)—,-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGF-NH—CH₂—O—CH₂—C(═O)—,-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—O—CH₂—C(═O)—,-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—,-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)—,-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—,-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂CH₂—C(═O)—,-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-KGGF—NH—CH₂—O—CH₂—C(═O)—,-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-KGGF—NH—CH₂CH₂—O—CH₂—C(═O)—,-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂CH₂—C(═O)—,-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-KGGFG-NH—CH₂—O—CH₂—C(═O)—,-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—.

The linker according to [108], which is selected from the followinggroup, provided that the left terminal is the connecting position to theantibody and the right terminal is the connecting position to theantitumor compound:

-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)—,-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—,-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF—NH—CH₂CH₂CH₂—C(═O)—,-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂CH₂—C(—O)—.

The linker according to [108], which is any of the followings, providedthat the left terminal is the connecting position to the antibody andthe right terminal is the connecting position to the antitumor compound:

-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)—,    and-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(—O)—.

The linker according to [108], which is selected from the followinggroup, provided that the left terminal is the connecting position to theantibody and the right terminal is the connecting position to theantitumor compound:

-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)—,-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—,-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-KGGF—NH—CH₂CH₂CH₂—C(═O)—,-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂CH₂—C(═O)—.

The linker according to [108], which is any of the followings, providedthat the left terminal is the connecting position to the antibody andthe right terminal is the connecting position to the antitumor compound:

-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)—, and-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—.

The linker according to [108], which is selected from the followinggroup, provided that the left terminal is the connecting position to theantibody and the right terminal is the connecting position to theantitumor compound:

-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂CH₂—C(═O)—,-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—,-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGF—NH—CH₂CH₂CH₂—C(═O)—,-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂CH₂—C(═O)—.

The linker according to [108], which is any of the followings, providedthat the left terminal is the connecting position to the antibody andthe right terminal is the connecting position to the antitumor compound:

-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)—,    and-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—.

The linker according to [108], which is selected from the followinggroup, provided that the left terminal is the connecting position to theantibody and the right terminal is the connecting position to theantitumor compound:

-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—,-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGF—,-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-,-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGFG-,-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF—,-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-KGGF—,-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-,-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-KGGFG-,-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGF—,-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGF—,-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-,-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGFG-,-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—,-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF—,-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-,-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGFG-.

The linker according to [108], which is selected from the followinggroup, provided that the left terminal is the connecting position to theantibody and the right terminal is the connecting position to theantitumor compound:

-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—,-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-,-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGFG-.

The linker according to [108], which is any of the followings, providedthat the left terminal is the connecting position to the antibody andthe right terminal is the connecting position to the antitumor compound:

-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-, and-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGFG-.

The linker according to [108], which has the following structure,provided that the left terminal is the connecting position to theantibody and the right terminal is the connecting position to theantitumor compound:

-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-.

The linker according to [108], which is any of the followings, providedthat the left terminal is the connecting position to the antibody andthe right terminal is the connecting position to the antitumor compound:

-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-, and-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-KGGFG-.

The linker according to [108], which has the following structure,provided that the left terminal is the connecting position to theantibody and the right terminal is the connecting position to theantitumor compound:

-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-.

The linker according to [108], which is any of the followings, providedthat the left terminal is the connecting position to the antibody andthe right terminal is the connecting position to the antitumor compound:

-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-,    and-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGFG-.

The linker according to [108], which has the following structure,provided that the left terminal is the connecting position to theantibody and the right terminal is the connecting position to theantitumor compound:

-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-.

The linker according to [108], which is selected from the followinggroup, provided that the left terminal is the connecting position to theantibody and the right terminal is the connecting position to theantitumor compound:

-   -(Succinimid-3-yl-N)—CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)—,-   -(Succinimid-3-yl-N)—CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)—,-   -(Succinimid-3-yl-N)—CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)—,-   -(Succinimid-3-yl-N)—CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)—.

The linker according to [108], which is selected from the followinggroup, provided that the left terminal is the connecting position to theantibody and the right terminal is the connecting position to theantitumor compound:

-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)—,-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)—,-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)—,-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)—.

The linker according to [108], which is selected from the followinggroup, provided that the left terminal is the connecting position to theantibody and the right terminal is the connecting position to theantitumor compound:

-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)—,-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)—,-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)—,-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)—.

The linker according to [108], which is selected from the followinggroup, provided that the left terminal is the connecting position to theantibody and the right terminal is the connecting position to theantitumor compound:

-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)—,-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)—,-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)—,-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)—.

The linker according to [108], which has the following structure,provided that the left terminal is the connecting position to theantibody and the right terminal is the connecting position to theantitumor compound:

-   -(Succinimid-3-yl-N)—CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-.

The linker according to [108], which has the following structure,provided that the left terminal is the connecting position to theantibody and the right terminal is the connecting position to theantitumor compound:

-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-.

The linker according to [108], which has the following structure,provided that the left terminal is the connecting position to theantibody and the right terminal is the connecting position to theantitumor compound:

-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-.

The linker according to [108], which has the following structure,provided that the left terminal is the connecting position to theantibody and the right terminal is the connecting position to theantitumor compound:

-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-.

The linker according to [108], which is any of the followings, providedthat the left terminal is the connecting position to the antibody andthe right terminal is the connecting position to the antitumor compound:

-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-GGFGG-, and-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-GGFGGG-.

The linker according to [108], which is any of the followings, providedthat the left terminal is the connecting position to the antibody andthe right terminal is the connecting position to the antitumor compound:

-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-GGFGG-, and-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-GGFGGG-.

The linker according to [108], which is any of the followings, providedthat the left terminal is the connecting position to the antibody andthe right terminal is the connecting position to the antitumor compound:

-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-GGFGG-,    and-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-GGFGGG-.

The linker according to [108], which is any of the followings, providedthat the left terminal is the connecting position to the antibody andthe right terminal is the connecting position to the antitumor compound:

-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-GGFGG-, and-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-GGFGGG-.

Here, in the linker according to any one of [109] to [135],—(N-ly-3-diminiccuS)- has a structure represented by the followingformula:

which is connected to L² at position 3 thereof and is connected to amethylene group in the linker structure containing this structure on thenitrogen atom at position 1,—(N-ly-3-diminiccuS)- has a structure represented by the followingformula:

which is connected to L² at position 3 thereof and is connected to amethylene group in the linker structure containing this structure on thenitrogen atom at position 1, andcyc.Hex(1,4) represents a 1,4-cyclohexylene group.

A method for producing an antibody-drug conjugate comprising reacting acompound represented by the following formula:

-   Q-L^(1a)-(CH₂)n^(Q)-C(═O)-L^(2a)-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX),    or-   Q-L^(1a)-(CH₂)n^(Q)-C(═O)-L^(2a)-L^(P)-(NH-DX)    with an antibody or a reactive derivative thereof and conjugating a    drug-linker moiety to the antibody by a method for forming a    thioether bond at a disulfide bond moiety present in a hinge part of    the antibody, or by a method for forming an amide bond at an amino    group present on a side chain of an amino acid constituting the    antibody or at the terminal amino group.

In the formula, Q represents (maleimid-N-yl)-, HS—, X—CH₂—C(═O)—NH—, or(Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—,

X represents a bromine atom or an iodine atom,L^(1a) represents —CH[—(CH₂)n³-COOH]- or a single bond,n^(Q) represents an integer of 0 to 8,L^(2a) represents —NH—(CH₂—CH₂—O) n⁶-CH₂—CH₂—C(═O)—,—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)—, or a single bond,

wherein n⁶ represents an integer of 0 to 6, n⁷ represents an integer of1 to 4,

L^(P) represents a peptide residue consisting of 3 to 8 amino acids,n¹ represents an integer of 0 to 6,L^(a) represents —C(═O)—NH—, —NR¹—(CH₂)n⁹-, —O—, or a single bond,

wherein n⁹ represents an integer of 1 to 6, R¹ represents a hydrogenatom, an alkyl group having 1 to 6 carbon atoms, —(CH₂)n^(a)-COOH, or—(CH₂)n^(b)-OH, n^(a) represents an integer of 1 to 4, n^(b) representsan integer of 1 to 6, L^(b) represents —CR²(—R³)—, —O—, —NR⁴—, or asingle bond,

wherein R² and R³ each independently represent a hydrogen atom, an alkylgroup having 1 to 6 carbon atoms, —(CH₂)n^(c)-NH₂, —(CH₂)n^(d)-COOH, or—(CH₂)n^(e)-OH, R⁴ represents a hydrogen atom or an alkyl group having 1to 6 carbon atoms, n^(c) represents an integer of 0 to 6, n^(d)represents an integer of 1 to 4, n^(e) represents an integer of 1 to 4,provided that when n^(c) is 0, R² and R³ are not the same as each other,

L^(c) represents —CH₂— or —C(═O)—,(maleimid-N-yl)- is a group represented by the following formula:

wherein the nitrogen atom is the connecting position,(Pyrrolidine-2,5-dione-N-yl) is a group represented by the followingformula:

wherein the nitrogen atom is the connecting position,—(NH-DX) is a group represented by the following formula:

wherein the nitrogen atom of the amino group at position 1 is theconnecting position,provided that any one or two or more of linkers ofL^(1a)-(CH₂)n^(Q)-C(═O)—, L², and L^(P) have a structure containing ahydrophilic structure,said hydrophilic structure means,when L^(P) has this structure,L^(P) is a peptide residue having a hydrophilic amino acid other thanglycine at the N terminal, orL^(P) is a peptide residue in which the C terminal is an oligopeptideconsisting of 2 or 3 or more glycines and is connected to the drug, andthe even in case that a hydrophilic amino acid is present at N terminal,no other hydrophilic amino acid than glycine is present thereat, as forlinker L^(1a)-(CH₂)n^(Q)-C(═O)—, the case in whichL^(1a)-(CH₂)n^(Q)-C(═O)— is —CH[—(CH₂)n³-COOH]—C(═O)—, or as for linkerL^(2a), the case in which L^(2a) is —N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)—.

The method for producing an antibody-drug conjugate according to [136],wherein the method for conjugating a drug-linker moiety to an antibodyis a method of reducing the antibody and thereafter forming a thioetherbond by the reaction of the antibody with the compound in which Q is amaleimidyl group or X—CH₂—C(═O)—NH—,

a method of forming an amide bond by the reaction of the antibody withthe compound in which Q is (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—, ora method of reacting the antibody with a compound represented by theformula Q¹-L^(1a)-(CH₂)n^(Q)-C(═O)-Q² wherein Q¹ represents(Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—,(3-Sulfo-pyrrolidine-2,5-dione-N-yl)-O—C(═O)—,

R^(Q)—O—C(═N)—, or O═C═N—,

L^(1a) represents -cyc.Hex(1,4)-CH₂—, an alkylene group having 1 to 10carbon atoms, a phenylene group, —(CH₂)n⁴-C(═O)—,—(CH₂)n^(4a)-NH—C(═O)—(CH₂)n^(4b)-, or—(CH₂)n^(4a)-NH—C(═O)-cyc.Hex(1,4)-CH₂—,Q² represents (maleimid-N-yl), a halogen atom, or —S—S-(2-Pyridyl),R^(Q) represents an alkyl group having 1 to 6 carbon atoms,n⁴ represents an integer of 1 to 8, n^(4a) represents an integer of 0 to6, n^(4b) represents an integer of 1 to 6,(3-Sulfo-pyrrolidine-2,5-dione-N-yl)- is a group represented by thefollowing formula:

wherein the nitrogen atom is the connecting position, this sulfonic acidis capable of forming a lithium salt, sodium salt, or potassium salt,cyc.Hex(1,4) represents a 1,4-cyclohexylene group, and (2-Pyridyl)represents a 2-pyridyl groupand thereafter reacting the antibody with the compound in which Q is SHto form a drug-linker structure by an amide bond.

The method for producing an antibody-drug conjugate according to [136]or [137], wherein the compound represented by the following formula:

-   Q-L^(1a)-(CH₂)n^(Q)-C(═O)-L^(2a)-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX),    or Q-L^(1a)-(CH₂)n^(Q)-C(═O)-L^(2a)-L^(P)-(NH-DX)    is a compound according to any one of [87] to [107].

A method for producing an antibody-drug conjugate produced by aproduction method according to any one of [136] to [138].

Advantageous Effects of Invention

With an antibody-drug conjugate having an antitumor compound exatecanconjugated via a linker with a specific structure, an excellentantitumor effect can be achieved.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows an amino acid sequence of B7-H3 variant 1 (SEQ ID NO: 1).

FIG. 2 shows an amino acid sequence of B7-H3 variant 2 (SEQ ID NO: 2).

FIG. 3 shows an amino acid sequence of an M30-H1-type heavy chain (SEQID NO: 9).

FIG. 4 shows an amino acid sequence of an M30-H2-type heavy chain (SEQID NO: 10).

FIG. 5 shows an amino acid sequence of an M30-H3-type heavy chain (SEQID NO: 11).

FIG. 6 shows an amino acid sequence of an M30-H4-type heavy chain (SEQID NO: 12).

FIG. 7 shows an amino acid sequence of an M30-L1-type light chain (SEQID NO: 13).

FIG. 8 shows an amino acid sequence of an M30-L2-type light chain (SEQID NO: 14).

FIG. 9 shows an amino acid sequence of an M30-L3-type light chain (SEQID NO: 15).

FIG. 10 shows an amino acid sequence of an M30-L4-type light chain (SEQID NO: 16).

FIG. 11 shows an amino acid sequence of an M30-L5-type light chain (SEQID NO: 17).

FIG. 12 shows an amino acid sequence of an M30-L6-type light chain (SEQID NO: 18).

FIG. 13 shows an amino acid sequence of an M30-L7-type light chain (SEQID NO: 19).

FIG. 14 shows an amino acid sequence of an M30 antibody heavy chain (SEQID NO: 20).

FIG. 15 shows an amino acid sequence of an M30 antibody light chain (SEQID NO: 21).

FIG. 16 shows a nucleotide sequence of B7-H3 variant 1 (SEQ ID NO: 26).

FIG. 17 shows the effects of an M30-H1-L4P antibody and antibody-drugconjugates (1), (2), (18), and (19) administered at 10 mg/kg on humanmelanoma line A375 cells transplanted in mice. The line with openrhombuses depicts results about untreated tumor, the line with filledrhombuses depicts the effect of the M30-H1-L4P antibody, the line withfilled squares depicts the effect of the antibody-drug conjugate (1),the line with open squares depicts the effect of the antibody-drugconjugate (2), the line with filled triangles depicts the effect of theantibody-drug conjugate (18), and the line with open triangles depictsthe effect of the antibody-drug conjugate (19).

FIG. 18 shows the effects of the antibody-drug conjugates (2) and (19)administered at 1 mg/kg and 3 mg/kg on human melanoma line A375 cellstransplanted in mice. The line with open rhombuses depicts results aboutuntreated tumor, the line with filled squares depicts the effect of theantibody-drug conjugate (2) administered at 1 mg/kg, the line with opensquares depicts the effect of the antibody-drug conjugate (2)administered at 3 mg/kg, the line with filled circles depicts the effectof the antibody-drug conjugate (19) administered at 1 mg/kg, and theline with open circles depicts the effect of the antibody-drug conjugate(19) administered at 3 mg/kg.

FIG. 19 shows the effects of an M30-H1-L4P antibody and theantibody-drug conjugates (1), (2), (18), and (19) administered at 10mg/kg on human non-small cell lung cancer line Calu-6 cells transplantedin mice. The line with open rhombuses depicts results about untreatedtumor, the line with filled rhombuses depicts the effect of theM30-H1-L4P antibody, the line with filled squares depicts the effect ofthe antibody-drug conjugate (1), the line with open squares depicts theeffect of the antibody-drug conjugate (2), the line with filledtriangles depicts the effect of the antibody-drug conjugate (18), andthe line with open triangles depicts the effect of the antibody-drugconjugate (19).

FIG. 20 shows the effects of antibody-drug conjugates (3), (20), and(30) administered at 3 mg/kg and 10 mg/kg on human melanoma line A375cells transplanted in mice. The line with open rhombuses depicts resultsabout untreated tumor, the dotted line with filled squares depicts theeffect of the antibody-drug conjugate (3) administered at 3 mg/kg, thesolid line with filled squares depicts the effect of the antibody-drugconjugate (3) administered at 10 mg/kg, the dotted line with filledtriangles depicts the effect of the antibody-drug conjugate (20)administered at 3 mg/kg, the solid line with filled triangles depictsthe effect of the antibody-drug conjugate (20) administered at 10 mg/kg,the dotted line with filled circles depicts the effect of theantibody-drug conjugate (30) administered at 3 mg/kg, and the solid linewith filled circles depicts the effect of the antibody-drug conjugate(30) administered at 10 mg/kg.

DESCRIPTION OF EMBODIMENTS

The antibody-drug conjugate of the present invention is an antitumordrug in which an antitumor antibody is conjugated to an antitumorcompound via a linker structure moiety and explained in detailhereinbelow.

[Antibody]

The antibody used in the antibody-drug conjugate of the presentinvention means an immunoglobulin and is a molecule containing anantigen-binding site immunospecifically binding to an antigen. The classof the antibody of the present invention may be any of IgG, IgE, IgM,IgD, IgA, and IgY and is preferably IgG. The subclass of the antibody ofthe present invention may be any of IgG1, IgG2, IgG3, IgG4, IgA1, andIgA2 and is preferably IgG1 or IgG2. The antibody may be derived fromany species, and preferred examples of the species can include humans,rats, mice, and rabbits. In case when derived from other than humanspecies, it is preferably chimerized or humanized using a well knowntechnique. The antibody of the present invention may be a polyclonalantibody or a monoclonal antibody and is preferably a monoclonalantibody.

The antibody of the present invention may be those which is capable oftargeting tumor cells. Since the antibody of the present invention isconjugated with a drug having antitumor activity via a linker, theantibody preferably possesses one or more of a property of recognizing atumor cell, a property of binding to a tumor cell, a property ofinternalizing in a tumor cell, and a property of damaging a tumor cell.

The binding activity of the antibody against tumor cells can beconfirmed using flow cytometry. The internalization of the antibody intotumor cells can be confirmed using (1) an assay of visualizing anantibody incorporated in cells under a fluorescence microscope using asecondary antibody (fluorescently labeled) binding to the therapeuticantibody (Cell Death and Differentiation (2008) 15, 751-761), (2) anassay of measuring the amount of fluorescence incorporated in cellsusing a secondary antibody (fluorescently labeled) binding to thetherapeutic antibody (Molecular Biology of the Cell, Vol. 15, 5268-5282,December 2004), or (3) a Mab-ZAP assay using an immunotoxin binding tothe therapeutic antibody wherein the toxin is released uponincorporation into cells to inhibit cell growth (Bio Techniques 28:162-165, January 2000).

The antitumor activity of the antibody refers to a cytotoxic activity orcytocidal effect against tumor cells and can be confirmed in vitro bydetermining inhibitory activity against cell growth. For example, acancer cell line overexpressing a target protein for the antibody iscultured, and the antibody is added at varying concentrations into theculture system to determine an inhibitory activity against focusformation, colony formation, and spheroid growth. The antitumor activitycan be confirmed in vivo, for example, by administering the antibody toa nude mouse with a transplanted tumor cell line highly expressing thetarget protein, and determining change in the cancer cell. Since thedrug conjugated in the antibody-drug conjugate exerts an antitumoreffect, it is more preferred but not essential that the antibody itselfshould have an antitumor effect. For exerting the antitumor effect andalso for specifically and selectively damaging tumor cells by the drug,it is important and also preferred that the antibody should have theproperty of internalizing to migrate into tumor cells.

Examples of such an antibody can include, but not limited to, ananti-A33 antibody, an anti-B7-H3 antibody, an anti-CanAg antibody, ananti-CD20 antibody, an anti-CD22 antibody, an anti-CD30 antibody, ananti-CD33 antibody, an anti-CD56 antibody, an anti-CD70 antibody, ananti-CEA antibody, an anti-Cripto antibody, an anti-EphA2 antibody, ananti-G250 antibody, an anti-MUC1 antibody, an anti-GPNMB antibody, ananti-integrin antibody, an anti-PSMA antibody, an anti-tenascin-Cantibody, an anti-SLC44A4 antibody, and an anti-mesothelin antibody.

The antibody of the present invention is preferably an anti-CD30antibody, an anti-CD33 antibody, an anti-CD70 antibody, or an anti-B7-H3antibody, and more preferably an anti-B7-H3 antibody.

The antibody of the present invention can be yielded using a methodusually carried out in the art, which involves immunizing animals withan antigenic polypeptide and collecting and purifying antibodiesproduced in vivo. The origin of the antigen is not limited to humans,and the animals may be immunized with an antigen derived from anon-human animal such as a mouse, a rat and the like. In this case, thecross-reactivity of antibodies binding to the yielded heterologousantigen with human antigens can be tested to screen for an antibodyapplicable to a human disease.

Alternatively, antibody-producing cells which produce antibodies againstthe antigen are fused with myeloma cells according to a method known inthe art (e.g., Kohler and Milstein, Nature (1975) 256, p. 495-497; andKennet, R. ed., Monoclonal Antibodies, p. 365-367, Plenum Press, N.Y.(1980)) to establish hybridomas, from which monoclonal antibodies can inturn be yielded.

The antigen can be yielded by genetically engineering host cells toproduce a gene encoding the antigenic protein. Specifically, vectorsthat permit expression of the antigen gene are prepared and transferredto host cells so that the gene is expressed. The antigen thus expressedcan be purified.

The anti-CD30 antibody, the anti-CD33 antibody, and the anti-CD70antibody can yielded by an approach known in the art with reference toWO2002/043661, U.S. Pat. No. 5,773,001, and WO2006/113909, respectively.

The B7-H3 antibody used in the present invention is preferably thosehaving properties as described below.

(1) An antibody having the following properties:

(a) specifically binding to B7-H3,

(b) having antibody-dependent cell-mediated phagocytosis (ADCP)activity, and

(c) having antitumor activity in vivo.

(2) The antibody according to (1), wherein B7-H3 is a moleculecomprising the amino acid sequence represented by SEQ ID NO: 1 or 2.(3) The antibody according to (1) or (2), wherein the antibody has CDRH1comprising the amino acid sequence represented by SEQ ID NO: 3, CDRH2comprising the amino acid sequence represented by SEQ ID NO: 4, andCDRH3 comprising the amino acid sequence represented by SEQ ID NO: 5 asheavy chain complementarity determining regions, and CDRL1 comprisingthe amino acid sequence represented by SEQ ID NO: 6, CDRL2 comprisingthe amino acid sequence represented by SEQ ID NO: 7, and CDRL3comprising the amino acid sequence represented by SEQ ID NO: 8 as lightchain complementarity determining regions.(4) The antibody according to any of (1) to (3), wherein the constantregion thereof is a human-derived constant region.(5) The antibody according to any of (1) to (4), wherein the antibody isa humanized antibody.(6) The antibody according to (5), wherein the antibody has a heavychain variable region comprising an amino acid sequence selected fromthe group consisting of (a) an amino acid sequence described in aminoacid positions 20 to 141 in SEQ ID NO: 9, (b) an amino acid sequencedescribed in amino acid positions 20 to 141 in SEQ ID NO: 10, (c) anamino acid sequence described in amino acid positions 20 to 141 in SEQID NO: 11, (d) an amino acid sequence described in amino acid positions20 to 141 in SEQ ID NO: 12, (e) an amino acid sequence having at least95% or higher homology to any of the sequences (a) to (d), and (f) anamino acid sequence derived from any of the sequences (a) to (d) by thedeletions, replacements, or additions of at least one amino acid, and alight chain variable region comprising an amino acid sequence selectedfrom the group consisting of (g) an amino acid sequence described inamino acid positions 21 to 128 in SEQ ID NO: 13, (h) an amino acidsequence described in amino acid positions 21 to 128 in SEQ ID NO: 14,(i) an amino acid sequence described in amino acid positions 21 to 128in SEQ ID NO: 15, (j) an amino acid sequence described in amino acidpositions 21 to 128 in SEQ ID NO: 16, (k) an amino acid sequencedescribed in amino acid positions 21 to 128 in SEQ ID NO: 17, (l) anamino acid sequence described in amino acid positions 21 to 128 in SEQID NO: 18, (m) an amino acid sequence described in amino acid positions21 to 128 in SEQ ID NO: 19, (n) an amino acid sequence having at least95% or higher homology to any of the sequences (g) to (m), and (o) anamino acid sequence derived from any of the sequences (g) to (m) by thedeletions, replacements, or additions of at least one amino acid.(7) The antibody according to (6), wherein the antibody has a heavychain variable region and a light chain variable region selected fromthe group consisting of a heavy chain variable region comprising anamino acid sequence described in amino acid positions 20 to 141 in SEQID NO: 9 and a light chain variable region comprising an amino acidsequence described in amino acid positions 21 to 128 in SEQ ID NO: 13, aheavy chain variable region comprising an amino acid sequence describedin amino acid positions 20 to 141 in SEQ ID NO: 9 and a light chainvariable region comprising an amino acid sequence described in aminoacid positions 21 to 128 in SEQ ID NO: 14, a heavy chain variable regioncomprising an amino acid sequence described in amino acid positions 20to 141 in SEQ ID NO: 9 and a light chain variable region comprising anamino acid sequence described in amino acid positions 21 to 128 in SEQID NO: 15, a heavy chain variable region comprising an amino acidsequence described in amino acid positions 20 to 141 in SEQ ID NO: 9 anda light chain variable region comprising an amino acid sequencedescribed in amino acid positions 21 to 128 in SEQ ID NO: 16, a heavychain variable region comprising an amino acid sequence described inamino acid positions 20 to 141 in SEQ ID NO: 9 and a light chainvariable region comprising an amino acid sequence described in aminoacid positions 21 to 128 in SEQ ID NO: 17, a heavy chain variable regioncomprising an amino acid sequence described in amino acid positions 20to 141 in SEQ ID NO: 9 and a light chain variable region comprising anamino acid sequence described in amino acid positions 21 to 128 in SEQID NO: 18, a heavy chain variable region comprising an amino acidsequence described in amino acid positions 20 to 141 in SEQ ID NO: 9 anda light chain variable region comprising an amino acid sequencedescribed in amino acid positions 21 to 128 in SEQ ID NO: 19, a heavychain variable region comprising an amino acid sequence described inamino acid positions 20 to 141 in SEQ ID NO: 12 and a light chainvariable region comprising an amino acid sequence described in aminoacid positions 21 to 128 in SEQ ID NO: 13, a heavy chain variable regioncomprising an amino acid sequence described in amino acid positions 20to 141 in SEQ ID NO: 12 and a light chain variable region comprising anamino acid sequence described in amino acid positions 21 to 128 in SEQID NO: 14, a heavy chain variable region comprising an amino acidsequence described in amino acid positions 20 to 141 in SEQ ID NO: 12and a light chain variable region comprising an amino acid sequencedescribed in amino acid positions 21 to 128 in SEQ ID NO: 15, and aheavy chain variable region comprising an amino acid sequence describedin amino acid positions 20 to 141 in SEQ ID NO: 12 and a light chainvariable region comprising an amino acid sequence described in aminoacid positions 21 to 128 in SEQ ID NO: 16.(8) The antibody according to (6) or (7), wherein the antibody comprisesa heavy chain and a light chain selected from the group consisting of aheavy chain comprising an amino acid sequence described in amino acidpositions 20 to 471 in SEQ ID NO: 9 and a light chain comprising anamino acid sequence described in amino acid positions 21 to 233 in SEQID NO: 13, a heavy chain comprising an amino acid sequence described inamino acid positions 20 to 471 in SEQ ID NO: 9 and a light chaincomprising an amino acid sequence described in amino acid positions 21to 233 in SEQ ID NO: 14, a heavy chain comprising an amino acid sequencedescribed in amino acid positions 20 to 471 in SEQ ID NO: 9 and a lightchain comprising an amino acid sequence described in amino acidpositions 21 to 233 in SEQ ID NO: 15, a heavy chain comprising an aminoacid sequence described in amino acid positions 20 to 471 in SEQ ID NO:9 and a light chain comprising an amino acid sequence described in aminoacid positions 21 to 233 in SEQ ID NO: 16, a heavy chain comprising anamino acid sequence described in amino acid positions 20 to 471 in SEQID NO: 9 and a light chain comprising an amino acid sequence describedin amino acid positions 21 to 233 in SEQ ID NO: 17, a heavy chaincomprising an amino acid sequence described in amino acid positions 20to 471 in SEQ ID NO: 9 and a light chain comprising an amino acidsequence described in amino acid positions 21 to 233 in SEQ ID NO: 18, aheavy chain comprising an amino acid sequence described in amino acidpositions 20 to 471 in SEQ ID NO: 9 and a light chain comprising anamino acid sequence described in amino acid positions 21 to 233 in SEQID NO: 19, a heavy chain comprising an amino acid sequence described inamino acid positions 20 to 471 in SEQ ID NO: 12 and a light chaincomprising an amino acid sequence described in amino acid positions 21to 233 in SEQ ID NO: 13, a heavy chain comprising an amino acid sequencedescribed in amino acid positions 20 to 471 in SEQ ID NO: 12 and a lightchain comprising an amino acid sequence described in amino acidpositions 21 to 233 in SEQ ID NO: 14, a heavy chain comprising an aminoacid sequence described in amino acid positions 20 to 471 in SEQ ID NO:12 and a light chain comprising an amino acid sequence described inamino acid positions 21 to 233 in SEQ ID NO: 15, and a heavy chaincomprising an amino acid sequence described in amino acid positions 20to 471 in SEQ ID NO: 12 and a light chain comprising an amino acidsequence described in amino acid positions 21 to 233 in SEQ ID NO: 16.(9) The antibody according to any of (14) to (16), wherein the antibodycomprises a heavy chain and a light chain selected from the groupconsisting of a heavy chain comprising the amino acid sequencerepresented by SEQ ID NO: 9 and a light chain comprising the amino acidsequence represented by SEQ ID NO: 13, a heavy chain comprising theamino acid sequence represented by SEQ ID NO: 9 and a light chaincomprising the amino acid sequence represented by SEQ ID NO: 14, a heavychain comprising the amino acid sequence represented by SEQ ID NO: 9 anda light chain comprising the amino acid sequence represented by SEQ IDNO: 15, a heavy chain comprising the amino acid sequence represented bySEQ ID NO: 9 and a light chain comprising the amino acid sequencerepresented by SEQ ID NO: 16, a heavy chain comprising the amino acidsequence represented by SEQ ID NO: 9 and a light chain comprising theamino acid sequence represented by SEQ ID NO: 17, a heavy chaincomprising the amino acid sequence represented by SEQ ID NO: 9 and alight chain comprising the amino acid sequence represented by SEQ ID NO:18, a heavy chain comprising the amino acid sequence represented by SEQID NO: 9 and a light chain comprising the amino acid sequencerepresented by SEQ ID NO: 19, a heavy chain comprising the amino acidsequence represented by SEQ ID NO: 12 and a light chain comprising theamino acid sequence represented by SEQ ID NO: 13, a heavy chaincomprising the amino acid sequence represented by SEQ ID NO: 12 and alight chain comprising the amino acid sequence represented by SEQ ID NO:14, a heavy chain comprising the amino acid sequence represented by SEQID NO: 12 and a light chain comprising the amino acid sequencerepresented by SEQ ID NO: 15, and a heavy chain comprising the aminoacid sequence represented by SEQ ID NO: 12 and a light chain comprisingthe amino acid sequence represented by SEQ ID NO: 16.(10) The antibody according to (8) or (9), wherein the antibody lacks anamino acid at the carboxy terminus of the amino acid sequencerepresented by SEQ ID NO: 9 or 12 in the heavy chain.(11) An antibody yielded by a method for producing the antibodyaccording to any of (1) to (10), the method comprising the steps of:culturing a host cell transformed with an expression vector containing apolynucleotide encoding the antibody; and collecting the antibody ofinterest from the cultures yielded in the preceding step.(12) The antibody according to any of (1) to (11), wherein themodification of a glycan is regulated in order to enhanceantibody-dependent cytotoxic activity.

Hereinafter, the B7-H3 antibody used in the invention is described.

The terms “cancer” and “tumor” as used herein are used with the samemeaning.

The term “gene” as used herein includes not only DNA, but also mRNAthereof, cDNA thereof and cRNA thereof.

The term “polynucleotide” as used herein is used with the same meaningas a nucleic acid and also includes DNA, RNA, probes, oligonucleotides,and primers.

The terms “polypeptide” and “protein” as used herein are used withoutdistinction.

The term “cell” as used herein also includes cells in an animalindividual and cultured cells.

The term “B7-H3” as used herein is used in the same meaning as B7-H3protein, and also refers to B7-H3 variant 1 and/or B7-H3 variant 2.

The term “CDR” as used herein refers to a complementarity determiningregion (CDR), and it is known that each heavy and light chain of anantibody molecule has three complementarity determining regions (CDRs).The CDR is also called the hypervariable region, and is present in avariable region of each heavy and light chain of an antibody. It is asite which has unusually high variability in its primary structure, andthere are three separate CDRs in the primary structure of each heavy andlight polypeptide chain. In this specification, as for the CDRs of anantibody, the CDRs of the heavy chain are represented by CDRH1, CDRH2,and CDRH3 from the amino-terminal side of the amino acid sequence of theheavy chain, and the CDRs of the light chain are represented by CDRL1,CDRL2, and CDRL3 from the amino-terminal side of the amino acid sequenceof the light chain. These sites are proximate to one another in thetertiary structure and determine the specificity for an antigen to whichthe antibody binds.

The phrase “hybridization is performed under stringent conditions” asused herein refers to a process in which hybridization is performedunder conditions under which identification can be achieved byperforming hybridization at 68° C. in a commercially availablehybridization solution ExpressHyb Hybridization Solution (manufacturedby Clontech, Inc.) or by performing hybridization at 68° C. in thepresence of 0.7 to 1.0 M NaCl using a filter having DNA immobilizedthereon, followed by performing washing at 68° C. using 0.1 to 2×SSCsolution (1×SSC solution is composed of 150 mM NaCl and 15 mM sodiumcitrate) or under conditions equivalent thereto.

1. B7-H3

B7-H3 is a member of the B7 family expressed on antigen-presenting cellsas a co-stimulatory molecule, and is considered to act on a receptor onT cells to enhance or suppress immune activity.

B7-H3 is a protein having a single-pass transmembrane structure, and theN-terminal extracellular domain of B7-H3 contains two variants. TheB7-H3 variant 1 (4Ig-B7-H3) contains a V-like or C-like Ig domain at twosites, respectively, and the B7-H3 variant 2 (2Ig-B7-H3) contains aV-like or C-like Ig domain at one site, respectively.

As for B7-H3 to be used in the invention, B7-H3 can be directly purifiedfrom B7-H3-expressing cells of a human or a non-human mammal (such as arat or a mouse) and used, or a cell membrane fraction of theabove-described cells can be prepared and used. Further, B7-H3 can beyielded by in vitro synthesis thereof or production thereof in a hostcell through genetic engineering. In the genetic engineering,specifically, after B7-H3 cDNA is integrated into a vector capable ofexpressing B7-H3 cDNA, B7-H3 can be yielded by synthesizing it in asolution containing an enzyme, a substrate and an energy substancerequired for transcription and translation, or by expressing B7-H3 inanother prokaryotic or eucaryotic transformed host cell.

The amino acid sequence of an open reading frame (ORF) of a human B7-H3variant 1 gene is represented by SEQ ID NO: 1 in the Sequence Listing.Further, the sequence of SEQ ID NO: 1 is shown in FIG. 1.

The amino acid sequence of an ORF of a human B7-H3 variant 2 gene isrepresented by SEQ ID NO: 2 in the Sequence Listing. Further, thesequence of SEQ ID NO: 2 is shown in FIG. 2.

Further, a protein which consists of an amino acid sequence wherein oneor several amino acids are substituted, deleted and/or added in any ofthe above-described amino acid sequences of B7-H3 and also has abiological activity equivalent to that of the protein is also includedin B7-H3.

Mature human B7-H3 variant 1 from which the signal sequence has beenremoved corresponds to an amino acid sequence consisting of amino acidresidues 27 to 534 of the amino acid sequence represented by SEQ IDNO: 1. Further, mature human B7-H3 variant 2 from which the signalsequence has been removed corresponds to an amino acid sequenceconsisting of amino acid residues 27 to 316 of the amino acid sequencerepresented by SEQ ID NO: 2.

2. Production of Anti-B7-H3 Antibody

The antibody against B7-H3 of the invention can be yielded by immunizingan animal with B7-H3 or an arbitrary polypeptide selected from the aminoacid sequence of B7-H3, and collecting and purifying the antibodyproduced in vivo according to a common procedure. The biological speciesof B7-H3 to be used as an antigen is not limited to being human, and ananimal can be immunized with B7-H3 derived from an animal other thanhumans such as a mouse or a rat. In this case, by examining thecross-reactivity between an antibody binding to the yielded heterologousB7-H3 and human B7-H3, an antibody applicable to a human disease can beselected.

Further, a monoclonal antibody can be yielded from a hybridomaestablished by fusing antibody-producing cells which produce an antibodyagainst B7-H3 with myeloma cells according to a known method (forexample, Kohler and Milstein, Nature, (1975) 256, pp. 495-497; Kennet,R. ed., Monoclonal Antibodies, pp. 365-367, Plenum Press, N.Y. (1980)).

B7-H3 to be used as an antigen can be yielded by expressing B7-H3 genein a host cell using genetic engine ring.

Specifically, a vector capable of expressing B7-H3 gene is produced, andthe resulting vector is transfected into a host cell to express thegene, and then, the expressed B7-H3 is purified. Hereinafter, a methodof yielding an antibody against B7-H3 is specifically described.

(1) Preparation of Antigen

Examples of the antigen to be used for producing the anti-B7-H3 antibodyinclude B7-H3, a polypeptide consisting of a partial amino acid sequencecomprising at least 6 consecutive amino acids of B7-H3, and a derivativeyielded by adding a given amino acid sequence or carrier thereto.

B7-H3 can be purified directly from human tumor tissues or tumor cellsand used. Further, B7-H3 can be yielded by synthesizing it in vitro orby producing it in a host cell by genetic engineering.

With respect to the genetic engineering, specifically, after B7-H3 cDNAis integrated into a vector capable of expressing B7-H3 cDNA, B7-H3 canbe yielded by synthesizing it in a solution containing an enzyme, asubstrate and an energy substance required for transcription andtranslation, or by expressing B7-H3 in another prokaryotic or eucaryotictransformed host cell.

Further, the antigen can also be yielded as a secretory protein byexpressing a fusion protein yielded by ligating the extracellular domainof B7-H3, which is a membrane protein, to the constant region of anantibody in an appropriate host-vector system.

B7-H3 cDNA can be yielded by, for example, a so-called PCR method inwhich a polymerase chain reaction (hereinafter referred to as “PCR”) isperformed using a cDNA library expressing B7-H3 cDNA as a template andprimers which specifically amplify B7-H3 cDNA (see Saiki, R. K., et al.,Science, (1988) 239, pp. 487-489).

As the in vitro synthesis of the polypeptide, for example, RapidTranslation System (RTS) manufactured by Roche Diagnostics, Inc. can beexemplified, but it is not limited thereto.

Examples of the prokaryotic host cells include Escherichia coli andBacillus subtilis. In order to transform the host cells with a targetgene, the host cells are transformed by a plasmid vector comprising areplicon, i.e., a replication origin derived from a species compatiblewith the host, and a regulatory sequence. Further, the vector preferablyhas a sequence capable of imposing phenotypic selectivity on thetransformed cell.

Examples of the eucaryotic host cells include vertebrate cells, insectcells, and yeast cells. As the vertebrate cells, for example, simian COScells (Gluzman, Y., Cell, (1981) 23, pp. 175-182, ATCC CRL-1650), murinefibroblasts NIH3T3 (ATCC No. CRL-1658), and dihydrofolatereductase-deficient strains (Urlaub, G. and Chasin, L. A., Proc. Natl.Acad. Sci. USA (1980) 77, pp. 4126-4220) of Chinese hamster ovariancells (CHO cells; ATCC: CCL-61); and the like are often used, however,the cells are not limited thereto.

The thus yielded transformant can be cultured according to a commonprocedure, and by the culturing of the transformant, a targetpolypeptide is produced intracellularly or extracellularly.

A suitable medium to be used for the culturing can be selected fromvarious commonly used culture media depending on the employed hostcells. If Escherichia coli is employed, for example, an LB mediumsupplemented with an antibiotic such as ampicillin or IPMG as needed canbe used.

A recombinant protein produced intracellularly or extracellularly by thetransformant through such culturing can be separated and purified by anyof various known separation methods utilizing the physical or chemicalproperty of the protein.

Specific examples of the methods include treatment with a common proteinprecipitant, ultrafiltration, various types of liquid chromatographysuch as molecular sieve chromatography (gel filtration), adsorptionchromatography, ion exchange chromatography, and affinitychromatography, dialysis, and a combination thereof.

Further, by attaching a tag of six histidine residues to a recombinantprotein to be expressed, the protein can be efficiently purified with anickel affinity column. Alternatively, by attaching the IgG Fc region toa recombinant protein to be expressed, the protein can be efficientlypurified with a protein A column.

By combining the above-described methods, a large amount of a targetpolypeptide can be easily produced in high yield and high purity.

(2) Production of Anti-B7-H3 Monoclonal Antibody

Examples of the antibody specific binding to B7-H3 include a monoclonalantibody specific binding to B7-H3, and a method of yielding theantibody is as described below.

The production of a monoclonal antibody generally requires the followingoperational steps of:

(a) purifying a biopolymer to be used as an antigen;

(b) preparing antibody-producing cells by immunizing an animal byinjection of the antigen, collecting the blood, assaying its antibodytiter to determine when the spleen is excised;

(c) preparing myeloma cells (hereinafter referred to as “myeloma”);

(d) fusing the antibody-producing cells with the myeloma;

(e) screening a group of hybridomas producing a desired antibody;

(f) dividing the hybridomas into single cell clones (cloning);

(g) optionally, culturing the hybridoma or rearing an animal implantedwith the hybridoma for producing a large amount of a monoclonalantibody;

(h) examining the thus produced monoclonal antibody for biologicalactivity and binding specificity, or assaying the same for properties asa labeled reagent; and the like.

Hereinafter, the method of producing a monoclonal antibody will bedescribed in detail following the above steps, however, the method isnot limited thereto, and, for example, antibody-producing cells otherthan spleen cells and myeloma can be used.

(a) Purification of Antigen

As the antigen, B7-H3 prepared by the method as described above or apartial peptide thereof can be used.

Further, a membrane fraction prepared from recombinant cells expressingB7-H3 or the recombinant cells expressing B7-H3 themselves, and also apartial peptide of the protein of the invention chemically synthesizedby a method known to those skilled in the art can also be used as theantigen.

(b) Preparation of Antibody-Producing Cells

The antigen yielded in the step (a) is mixed with an adjuvant such asFreund's complete or incomplete adjuvant or aluminum potassium sulfateand the resulting mixture is used as an immunogen to immunize anexperimental animal. As the experimental animal, any animal used in aknown hybridoma production method can be used without any trouble.Specifically, for example, a mouse, a rat, a goat, sheep, cattle, ahorse, or the like can be used. However, from the viewpoint of ease ofavailability of myeloma cells to be fused with the extractedantibody-producing cells, a mouse or a rat is preferably used as theanimal to be immunized.

Further, the strain of a mouse or a rat to be used is not particularlylimited, and in the case of a mouse, for example, various strains suchas A, AKR, BALB/c, BDP, BA, CE, C3H, 57BL, C57BL, C57L, DBA, FL, HTH,HT1, LP, NZB, NZW, RF, R III, SJL, SWR, WB, and 129 and the like can beused, and in the case of a rat, for example, Wistar, Low, Lewis,Sprague, Dawley, ACI, BN, Fischer and the like can be used.

These mice and rats are commercially available frombreeders/distributors of experimental animals, for example, CLEA Japan,Inc. and Charles River Laboratories Japan, Inc.

Among these, in consideration of compatibility of fusing with myelomacells described below, in the case of a mouse, BALB/c strain, and in thecase of a rat, Wistar and Low strains are particularly preferred as theanimal to be immunized.

Further, in consideration of antigenic homology between humans and mice,it is also preferred to use a mouse having decreased biological functionto remove auto-antibodies, that is, a mouse with an autoimmune disease.

The age of such mouse or rat at the time of immunization is preferably 5to 12 weeks of age, more preferably 6 to 8 weeks of age.

In order to immunize an animal with B7-H3 or a recombinant thereof, forexample, a known method described in detail in, for example, Weir, D.M., Handbook of Experimental Immunology Vol. I. II. III., BlackwellScientific Publications, Oxford (1987), Kabat, E. A. and Mayer, M. M.,Experimental Immunochemistry, Charles C Thomas Publisher Springfield,Ill. (1964) or the like can be used.

Among these immunization methods, a preferred specific method in theinvention is, for example, as follows.

That is, first, a membrane protein fraction serving as the antigen orcells caused to express the antigen is/are intradermally orintraperitoneally administrated to an animal.

However, the combination of both routes of administration is preferredfor increasing the immunization efficiency, and when intradermaladministration is performed in the first half and intraperitonealadministration is performed in the latter half or only at the lastdosing, the immunization efficiency can be particularly increased.

The administration schedule of the antigen varies depending on the typeof animal to be immunized, individual difference or the like. However,in general, an administration schedule in which the frequency ofadministration of the antigen is 3 to 6 times and the dosing interval is2 to 6 weeks is preferred, and an administration schedule in which thefrequency of administration of the antigen is 3 to 4 times and thedosing interval is 2 to 4 weeks is more preferred.

Further, the dose of the antigen varies depending on the type of animal,individual differences or the like, however, the dose is generally setto 0.05 to 5 mg, preferably about 0.1 to 0.5 mg.

A booster immunization is performed 1 to 6 weeks, preferably 2 to 4weeks, more preferably 2 to 3 weeks after the administration of theantigen as described above.

The dose of the antigen at the time of performing the boosterimmunization varies depending on the type or size of animal or the like,however, in the case of, for example, a mouse, the dose is generally setto 0.05 to 5 mg, preferably 0.1 to 0.5 mg, more preferably about 0.1 to0.2 mg.

Spleen cells or lymphocytes including antibody-producing cells areaseptically removed from the immunized animal 1 to 10 days, preferably 2to 5 days, more preferably 2 to 3 days after the booster immunization.At this time, the antibody titer is measured, and if an animal having asufficiently increased antibody titer is used as a supply source of theantibody-producing cells, the subsequent procedure can be carried outmore efficiently.

Examples of the method of measuring the antibody titer to be used hereinclude an RIA method and an ELISA method, but the method is not limitedthereto.

For example, if an ELISA method is employed, the measurement of theantibody titer in the invention can be carried out according to theprocedures as described below.

First, a purified or partially purified antigen is adsorbed to thesurface of a solid phase such as a 96-well plate for ELISA, and thesurface of the solid phase having no antigen adsorbed thereto is coveredwith a protein unrelated to the antigen such as bovine serum albumin(hereinafter referred to as “BSA”). After washing the surface, thesurface is brought into contact with a serially-diluted sample (forexample, mouse serum) as a primary antibody to allow the antibody in thesample to bind to the antigen.

Further, as a secondary antibody, an antibody labeled with an enzymeagainst a mouse antibody is added and is allowed to bind to the mouseantibody. After washing, a substrate for the enzyme is added and achange in absorbance which occurs due to color development induced bydegradation of the substrate or the like is measured and the antibodytiter is calculated based on the measurement.

The separation of the antibody-producing cells from the spleen cells orlymphocytes of the immunized animal can be carried out according to aknown method (for example, Kohler et al., Nature (1975), 256, p. 495;Kohler et al., Eur. J. Immunol. (1977), 6, p. 511; Milstein et al.,Nature (1977), 266, p. 550; Walsh, Nature (1977), 266, p. 495). Forexample, in the case of spleen cells, a general method in which theantibody-producing cells are separated by homogenizing the spleen toyield the cells through filtration with a stainless steel mesh andsuspending the cells in Eagle's Minimum Essential Medium (MEM) can beemployed.

(c) Preparation of Myeloma Cells (Hereinafter Referred to as “Myeloma”)

The myeloma cells to be used for cell fusion are not particularlylimited and suitable cells can be selected from known cell lines.However, in consideration of convenience when a hybridoma is selectedfrom fused cells, it is preferred to use an HGPRT (hypoxanthine-guaninephosphoribosyl transferase) deficient strain whose selection procedurehas been established.

More specifically, examples of the HGPRT-deficient strain includeX63-Ag8(X63), NS1-ANS/1(NS1), P3X63-Ag8.U1(P3U1), X63-Ag8.653(X63.653),SP2/0-Ag14(SP2/0), MPC11-45.6TG1.7(45.6TG), FO, S149/5XXO, and BU.1derived from mice; 210.RSY3.Ag.1.2.3(Y3) derived from rats; andU266AR(SKO-007), GM1500-GTG-A12(GM1500), UC729-6, LICR-LOW-HMy2(HMy2)and 8226AR/NIP4-1(NP41) derived from humans. These HGPRT-deficientstrains are available from, for example, the American Type CultureCollection (ATCC) or the like.

These cell strains are subcultured in an appropriate medium such as an8-azaguanine medium [a medium yielded by adding 8-azaguanine to an RPMI1640 medium supplemented with glutamine, 2-mercaptoethanol, gentamicin,and fetal calf serum (hereinafter referred to as “FCS”)], Iscove'sModified Dulbecco's Medium (hereinafter referred to as “IMDM”), orDulbecco's Modified Eagle Medium (hereinafter referred to as “DMEM”). Inthis case, 3 to 4 days before performing cell fusion, the cells aresubcultured in a normal medium [for example, an ASF104 medium(manufactured by Ajinomoto Co., Ltd.) containing 10% FCS] to ensure notless than 2×10⁷ cells on the day of cell fusion.

(d) Cell Fusion

Fusion between the antibody-producing cells and the myeloma cells can beappropriately performed according to a known method (Weir, D. M.Handbook of Experimental Immunology Vol. I. II. III., BlackwellScientific Publications, Oxford (1987), Kabat, E. A. and Mayer, M. M.,Experimental Immunochemistry, Charles C Thomas Publisher, Springfield,Ill. (1964), etc.), under conditions such that the survival rate ofcells is not excessively reduced.

As such a method, for example, a chemical method in which theantibody-producing cells and the myeloma cells are mixed in a solutioncontaining a polymer such as polyethylene glycol at a highconcentration, a physical method using electric stimulation, or the likecan be used. Among these methods, a specific example of the chemicalmethod is as described below.

That is, in the case where polyethylene glycol is used in the solutioncontaining a polymer at a high concentration, the antibody-producingcells and the myeloma cells are mixed in a solution of polyethyleneglycol having a molecular weight of 1500 to 6000, more preferably 2000to 4000 at a temperature of from 30 to 40° C., preferably from 35 to 38°C. for 1 to 10 minutes, preferably 5 to 8 minutes.

(e) Selection of a Group of Hybridomas

The method of selecting hybridomas yielded by the above-described cellfusion is not particularly limited. Usually, an HAT (hypoxanthine,aminopterin, thymidine) selection method (Kohler et al., Nature (1975),256, p. 495; Milstein et al., Nature (1977), 266, p. 550) is used.

This method is effective when hybridomas are yielded using the myelomacells of an HGPRT-deficient strain which cannot survive in the presenceof aminopterin.

That is, by culturing unfused cells and hybridomas in an HAT medium,only hybridomas resistant to aminopterin are selectively allowed tosurvive and proliferate.

(f) Division into Single Cell Clone (Cloning)

As a cloning method for hybridomas, a known method such as amethylcellulose method, a soft agarose method, or a limiting dilutionmethod can be used (see, for example, Barbara, B. M. and Stanley, M. S.:Selected Methods in Cellular Immunology, W. H. Freeman and Company, SanFrancisco (1980)). Among these methods, particularly, athree-dimensional culture method such as a methylcellulose method ispreferred. For example, the group of hybridomas produced by cell fusionare suspended in a methylcellulose medium such as ClonaCell-HY SelectionMedium D (manufactured by StemCell Technologies, inc., #03804) andcultured. Then, the formed hybridoma colonies are collected, wherebymonoclonal hybridomas can be yielded. The collected respective hybridomacolonies are cultured, and a hybridoma which has been confirmed to havea stable antibody titer in an yielded hybridoma culture supernatant isselected as a B7-H3 monoclonal antibody-producing hybridoma strain.

Examples of the thus established hybridoma strain include B7-H3hybridoma M30. In this specification, an antibody produced by the B7-H3hybridoma M30 is referred to as “M30 antibody” or simply “M30”.

The heavy chain of the M30 antibody has an amino acid sequencerepresented by SEQ ID NO: 20 in the Sequence Listing. Further, the lightchain of the M30 antibody has an amino acid sequence represented by SEQID NO: 21 in the Sequence Listing. In the heavy chain amino acidsequence represented by SEQ ID NO: 20 in the Sequence Listing, an aminoacid sequence consisting of amino acid residues 1 to 19 is a signalsequence, an amino acid sequence consisting of amino acid residues 20 to141 is a variable region, and an amino acid sequence consisting of aminoacid residues 142 to 471 is a constant region. Further, in the lightchain amino acid sequence represented by SEQ ID NO: 21 in the SequenceListing, an amino acid sequence consisting of amino acid residues 1 to22 is a signal sequence, an amino acid sequence consisting of amino acidresidues 23 to 130 is a variable region, and an amino acid sequenceconsisting of amino acid residues 131 to 235 is a constant region.

(g) Preparation of Monoclonal Antibody by Culturing Hybridoma

By culturing the thus selected hybridoma, a monoclonal antibody can beefficiently yielded. However, prior to culturing, it is preferred toperform screening of a hybridoma which produces a target monoclonalantibody.

In such screening, a known method can be employed.

The measurement of the antibody titer in the invention can be carriedout by, for example, an ELISA method explained in item (b) describedabove.

The hybridoma yielded by the method described above can be stored in afrozen state in liquid nitrogen or in a freezer at −80° C. or below.

After completion of cloning, the medium is changed from an HT medium toa normal medium, and the hybridoma is cultured.

Large-scale culture is performed by rotation culture using a largeculture bottle or by spinner culture. From the supernatant yielded bythe large-scale culture, a monoclonal antibody which specifically bindsto the protein of the invention can be yielded by purification using amethod known to those skilled in the art such as gel filtration.

Further, the hybridoma is injected into the abdominal cavity of a mouseof the same strain as the hybridoma (for example, the above-describedBALB/c) or a Nu/Nu mouse to proliferate the hybridoma, whereby theascites containing a large amount of the monoclonal antibody of theinvention can be yielded.

In the case where the hybridoma is administrated in the abdominalcavity, if a mineral oil such as 2,6,10,14-tetramethyl pentadecane(pristane) is administrated 3 to 7 days prior thereto, a larger amountof the ascites can be yielded.

For example, an immunosuppressant is previously injected into theabdominal cavity of a mouse of the same strain as the hybridoma toinactivate T cells. 20 days thereafter, 10⁶ to 10⁷ hybridoma clone cellsare suspended in a serum-free medium (0.5 ml), and the suspension isadministrated in the abdominal cavity of the mouse. In general, when theabdomen is expanded and filled with the ascites, the ascites iscollected from the mouse. By this method, the monoclonal antibody can beyielded at a concentration which is about 100 times or much higher thanthat in the culture solution.

The monoclonal antibody yielded by the above-described method can bepurified by a method described in, for example, Weir, D. M.: Handbook ofExperimental Immunology Vol. I, II, III, Blackwell ScientificPublications, Oxford (1978).

The thus yielded monoclonal antibody has high antigen specificity forB7-H3.

(h) Assay of Monoclonal Antibody

The isotype and subclass of the thus yielded monoclonal antibody can bedetermined as follows.

First, examples of the identification method include an Ouchterlonymethod, an ELISA method, and an RIA method.

An Ouchterlony method is simple, but when the concentration of themonoclonal antibody is low, a condensation operation is required.

On the other hand, when an ELISA method or an RIA method is used, bydirectly reacting the culture supernatant with an antigen-adsorbed solidphase and using antibodies corresponding to various types ofimmunoglobulin isotypes and subclasses as secondary antibodies, theisotype and subclass of the monoclonal antibody can be identified.

In addition, as a simpler method, a commercially availableidentification kit (for example, Mouse Typer Kit manufactured by Bio-RadLaboratories, Inc.) or the like can also be used.

Further, the quantitative determination of a protein can be performed bythe Folin Lowry method and a method of calculation based on theabsorbance at 280 nm [1.4 (OD 280)=Immunoglobulin 1 mg/ml].

Further, even when the monoclonal antibody is separately andindependently yielded by performing again the steps of (a) to (h) in(2), it is possible to yield an antibody having a cytotoxic activityequivalent to that of the M30 antibody. As one example of such anantibody, an antibody which binds to the same epitope as the M30antibody can be exemplified. The M30 recognizes an epitope in the IgC1or IgC2 domain, which is a domain in the B7-H3 extracellular domain, andbinds to the IgC1 domain or the IgC2 domain or both. Therefore, as theepitope for the antibody of the invention, particularly, an epitopepresent in the IgC1 or IgC2 domain of B7-H3 can be exemplified. If anewly produced monoclonal antibody binds to a partial peptide or apartial tertiary structure to which the M30 antibody binds, it can bedetermined that the monoclonal antibody binds to the same epitope as theM30 antibody. Further, by confirming that the monoclonal antibodycompetes with the M30 antibody for the binding to B7-H3 (that is, themonoclonal antibody inhibits the binding between the M30 antibody andB7-H3), it can be determined that the monoclonal antibody binds to thesame epitope as the M30 antibody even if the specific epitope sequenceor structure has not been determined. When it is confirmed that themonoclonal antibody binds to the same epitope as the M30 antibody, themonoclonal antibody is strongly expected to have a cytotoxic activityequivalent to that of the M30 antibody.

(3) Other Antibodies

The antibody of the invention includes not only the above-describedmonoclonal antibody against B7-H3 but also a recombinant antibodyyielded by artificial modification for the purpose of decreasingheterologous antigenicity to humans such as a chimeric antibody, ahumanized antibody and a human antibody. These antibodies can beproduced using a known method.

As the chimeric antibody, an antibody in which antibody variable andconstant regions are derived from different species, for example, achimeric antibody in which a mouse- or rat-derived antibody variableregion is connected to a human-derived antibody constant region can beexemplified (see Proc. Natl. Acad. Sci. USA, 81, 6851-6855, (1984)).

As the humanized antibody, an antibody yielded by integrating only acomplementarity determining region (CDR) into a human-derived antibody(see Nature (1986) 321, pp. 522-525), and an antibody yielded bygrafting a part of the amino acid residues of the framework as well asthe CDR sequence to a human antibody by a CDR-grafting method (WO90/07861) can be exemplified.

However, the humanized antibody derived from the M30 antibody is notlimited to a specific humanized antibody as long as the humanizedantibody has all 6 types of CDR sequences of the M30 antibody and has anantitumor activity. The heavy chain variable region of the M30 antibodyhas CDRH1 (NYVMH) consisting of an amino acid sequence represented bySEQ ID NO: 3 in the Sequence Listing, CDRH2 (YINPYNDDVKYNEKFKG)consisting of an amino acid sequence represented by SEQ ID NO: 4 in theSequence Listing, and CDRH3 (WGYYGSPLYYFDY) consisting of an amino acidsequence represented by SEQ ID NO: 5 in the Sequence Listing. Further,the light chain variable region of the M30 antibody has CDRL1(RASSRLIYMH) consisting of an amino acid sequence represented by SEQ IDNO: 6 in the Sequence Listing, CDRL2 (ATSNLAS) consisting of an aminoacid sequence represented by SEQ ID NO: 7 in the Sequence Listing, andCDRL3 (QQWNSNPPT) consisting of an amino acid sequence represented bySEQ ID NO: 8 in the Sequence Listing.

As an example of the humanized antibody of a mouse antibody M30, anarbitrary combination of a heavy chain comprising a heavy chain variableregion consisting of any one of (1) an amino acid sequence consisting ofamino acid residues 20 to 141 of SEQ ID NO: 9, 10, 11, or 12 in theSequence Listing, (2) an amino acid sequence having a homology of atleast 95% or more with the amino acid sequence (1) described above, and(3) an amino acid sequence wherein one or several amino acids in theamino acid sequence (1) described above are deleted, substituted oradded and a light chain comprising a light chain variable regionconsisting of any one of (4) an amino acid sequence consisting of aminoacid residues 21 to 128 of SEQ ID NO: 13, 14, 15, 16, 17, 18, or 19 inthe Sequence Listing, (5) an amino acid sequence having a homology of atleast 95% or more with the amino acid sequence (4) described above, and(6) an amino acid sequence wherein one or several amino acids in theamino acid sequence (4) described above are deleted, substituted oradded can be exemplified.

The term “several” as used herein refers to 1 to 10, 1 to 9, 1 to 8, 1to 7, 1 to 6, 1 to 5, 1 to 4, 1 to 3, or 1 or 2.

As the amino acid substitution in this specification, a conservativeamino acid substitution is preferred. The conservative amino acidsubstitution refers to a substitution occurring within a group of aminoacids related to amino acid side chains. Preferred amino acid groups areas follows: an acidic group (aspartic acid and glutamic acid); a basicgroup (lysine, arginine, and histidine); a non-polar group (alanine,valine, leucine, isoleucine, proline, phenylalanine, methionine, andtryptophan); and an uncharged polar family (glycine, asparagine,glutamine, cysteine, serine, threonine, and tyrosine). More preferredamino acid groups are as follows: an aliphatic hydroxy group (serine andthreonine); an amide-containing group (asparagine and glutamine); analiphatic group (alanine, valine, leucine, and isoleucine); and anaromatic group (phenylalanine, tryptophan, and tyrosine). Such an aminoacid substitution is preferably performed within a range which does notimpair the properties of a substance having the original amino acidsequence.

As an antibody which has a preferred combination of a heavy chain and alight chain described above, an antibody consisting of a heavy chaincomprising a heavy chain variable region consisting of an amino acidsequence consisting of amino acid residues 20 to 141 of SEQ ID NO: 9 anda light chain comprising a light chain variable region consisting of anamino acid sequence consisting of amino acid residues 21 to 128 of SEQID NO: 13; an antibody consisting of a heavy chain comprising a heavychain variable region consisting of an amino acid sequence consisting ofamino acid residues 20 to 141 of SEQ ID NO: 9 and a light chaincomprising a light chain variable region consisting of an amino acidsequence consisting of amino acid residues 21 to 128 of SEQ ID NO: 14;an antibody consisting of a heavy chain comprising a heavy chainvariable region consisting of an amino acid sequence consisting of aminoacid residues 20 to 141 of SEQ ID NO: 9 and a light chain comprising alight chain variable region consisting of an amino acid sequenceconsisting of amino acid residues 21 to 128 of SEQ ID NO: 15; anantibody consisting of a heavy chain comprising a heavy chain variableregion consisting of an amino acid sequence consisting of amino acidresidues 20 to 141 of SEQ ID NO: 9 and a light chain comprising a lightchain variable region consisting of an amino acid sequence consisting ofamino acid residues 21 to 128 of SEQ ID NO: 16; an antibody consistingof a heavy chain comprising a heavy chain variable region consisting ofan amino acid sequence consisting of amino acid residues 20 to 141 ofSEQ ID NO: 9 and a light chain comprising a light chain variable regionconsisting of an amino acid sequence consisting of amino acid residues21 to 128 of SEQ ID NO: 17; an antibody consisting of a heavy chaincomprising a heavy chain variable region consisting of an amino acidsequence consisting of amino acid residues 20 to 141 of SEQ ID NO: 9 anda light chain comprising a light chain variable region consisting of anamino acid sequence consisting of amino acid residues 21 to 128 of SEQID NO: 18; an antibody consisting of a heavy chain comprising a heavychain variable region consisting of an amino acid sequence consisting ofamino acid residues 20 to 141 of SEQ ID NO: 9 and a light chaincomprising a light chain variable region consisting of an amino acidsequence consisting of amino acid residues 21 to 128 of SEQ ID NO: 19;an antibody consisting of a heavy chain comprising a heavy chainvariable region consisting of an amino acid sequence consisting of aminoacid residues 20 to 141 of SEQ ID NO: 12 and a light chain comprising alight chain variable region consisting of an amino acid sequenceconsisting of amino acid residues 21 to 128 of SEQ ID NO: 13; anantibody consisting of a heavy chain comprising a heavy chain variableregion consisting of an amino acid sequence consisting of amino acidresidues 20 to 141 of SEQ ID NO: 12 and a light chain comprising a lightchain variable region consisting of an amino acid sequence consisting ofamino acid residues 21 to 128 of SEQ ID NO: 14; an antibody consistingof a heavy chain comprising a heavy chain variable region consisting ofan amino acid sequence consisting of amino acid residues 20 to 141 ofSEQ ID NO: 12 and a light chain comprising a light chain variable regionconsisting of an amino acid sequence consisting of amino acid residues21 to 128 of SEQ ID NO: 15; and an antibody consisting of a heavy chaincomprising a heavy chain variable region consisting of an amino acidsequence consisting of amino acid residues 20 to 141 of SEQ ID NO: 12and a light chain comprising a light chain variable region consisting ofan amino acid sequence consisting of amino acid residues 21 to 128 ofSEQ ID NO: 16 can be exemplified.

Further, as an antibody which has a more preferred combination of aheavy chain and a light chain described above, an antibody consisting ofa heavy chain consisting of an amino acid sequence consisting of aminoacid residues 20 to 471 of SEQ ID NO: 9 and a light chain consisting ofan amino acid sequence consisting of amino acid residues 21 to 233 ofSEQ ID NO: 13; an antibody consisting of a heavy chain consisting of anamino acid sequence consisting of amino acid residues 20 to 471 of SEQID NO: 9 and a light chain consisting of an amino acid sequenceconsisting of amino acid residues 21 to 233 of SEQ ID NO: 14; anantibody consisting of a heavy chain consisting of an amino acidsequence consisting of amino acid residues 20 to 471 of SEQ ID NO: 9 anda light chain consisting of an amino acid sequence consisting of aminoacid residues 21 to 233 of SEQ ID NO: 15; an antibody consisting of aheavy chain consisting of an amino acid sequence consisting of aminoacid residues 20 to 471 of SEQ ID NO: 9 and a light chain consisting ofan amino acid sequence consisting of amino acid residues 21 to 233 ofSEQ ID NO: 16; an antibody consisting of a heavy chain consisting of anamino acid sequence consisting of amino acid residues 20 to 471 of SEQID NO: 9 and a light chain consisting of an amino acid sequenceconsisting of amino acid residues 21 to 233 of SEQ ID NO: 17; anantibody consisting of a heavy chain consisting of an amino acidsequence consisting of amino acid residues 20 to 471 of SEQ ID NO: 9 anda light chain consisting of an amino acid sequence consisting of aminoacid residues 21 to 233 of SEQ ID NO: 18; an antibody consisting of aheavy chain consisting of an amino acid sequence consisting of aminoacid residues 20 to 471 of SEQ ID NO: 9 and a light chain consisting ofan amino acid sequence consisting of amino acid residues 21 to 233 ofSEQ ID NO: 19; an antibody consisting of a heavy chain consisting of anamino acid sequence consisting of amino acid residues 20 to 471 of SEQID NO: 12 and a light chain consisting of an amino acid sequenceconsisting of amino acid residues 21 to 233 of SEQ ID NO: 13; anantibody consisting of a heavy chain consisting of an amino acidsequence consisting of amino acid residues 20 to 471 of SEQ ID NO: 12and a light chain consisting of an amino acid sequence consisting ofamino acid residues 21 to 233 of SEQ ID NO: 14; an antibody consistingof a heavy chain consisting of an amino acid sequence consisting ofamino acid residues 20 to 471 of SEQ ID NO: 12 and a light chainconsisting of an amino acid sequence consisting of amino acid residues21 to 233 of SEQ ID NO: 15; and an antibody consisting of a heavy chainconsisting of an amino acid sequence consisting of amino acid residues20 to 471 of SEQ ID NO: 12 and a light chain consisting of an amino acidsequence consisting of amino acid residues 21 to 233 of SEQ ID NO: 16can be exemplified.

Furthermore, as an antibody which has another more preferred combinationof a heavy chain and a light chain described above, an antibodyconsisting of a heavy chain consisting of an amino acid sequence of SEQID NO: 9 and a light chain consisting of an amino acid sequence of SEQID NO: 13; an antibody consisting of a heavy chain consisting of anamino acid sequence of SEQ ID NO: 9 and a light chain consisting of anamino acid sequence of SEQ ID NO: 14; an antibody consisting of a heavychain consisting of an amino acid sequence of SEQ ID NO: 9 and a lightchain consisting of an amino acid sequence of SEQ ID NO: 15; an antibodyconsisting of a heavy chain consisting of an amino acid sequence of SEQID NO: 9 and a light chain consisting of an amino acid sequence of SEQID NO: 16; an antibody consisting of a heavy chain consisting of anamino acid sequence of SEQ ID NO: 9 and a light chain consisting of anamino acid sequence of SEQ ID NO: 17; an antibody consisting of a heavychain consisting of an amino acid sequence of SEQ ID NO: 9 and a lightchain consisting of an amino acid sequence of SEQ ID NO: 18; an antibodyconsisting of a heavy chain consisting of an amino acid sequence of SEQID NO: 9 and a light chain consisting of an amino acid sequence of SEQID NO: 19; an antibody consisting of a heavy chain consisting of anamino acid sequence of SEQ ID NO: 12 and a light chain consisting of anamino acid sequence of SEQ ID NO: 13; an antibody consisting of a heavychain consisting of an amino acid sequence of SEQ ID NO: 12 and a lightchain consisting of an amino acid sequence of SEQ ID NO: 14; an antibodyconsisting of a heavy chain consisting of an amino acid sequence of SEQID NO: 12 and a light chain consisting of an amino acid sequence of SEQID NO: 15; and an antibody consisting of a heavy chain consisting of anamino acid sequence of SEQ ID NO: 12 and a light chain consisting of anamino acid sequence of SEQ ID NO: 16 can be exemplified.

By combining a sequence having a high homology with the above-describedheavy chain amino acid sequence with a sequence having a high homologywith the above-described light chain amino acid sequence, it is possibleto select an antibody having a cytotoxic activity equivalent to that ofeach of the above-described antibodies. Such a homology is generally ahomology of 80% or more, preferably a homology of 90% or more, morepreferably a homology of 95% or more, most preferably a homology of 99%or more. Further, by combining an amino acid sequence wherein one toseveral amino acid residues are substituted, deleted or added in theheavy chain or light chain amino acid sequence, it is also possible toselect an antibody having a cytotoxic activity equivalent to that ofeach of the above-described antibodies.

The homology between two amino acid sequences can be determined usingdefault parameters of Blast algorithm version 2.2.2 (Altschul, StephenF., Thomas L. Madden, Alejandro A. Schaffer, Jinghui Zhang, Zheng Zhang,Webb Miller, and David J. Lipman (1997), “Gapped BLAST and PSI-BLAST: anew generation of protein database search programs”, Nucleic Acids Res.25: 3389-3402). The Blast algorithm can be used also through theInternet by accessing the site www.ncbi.nlm.nih.gov/blast.

In the heavy chain amino acid sequence represented by SEQ ID NO: 9, 10,11 or 12 in the Sequence Listing, an amino acid sequence consisting ofamino acid residues 1 to 19 is a signal sequence, an amino acid sequenceconsisting of amino acid residues 20 to 141 is a variable region, and anamino acid sequence consisting of amino acid residues 142 to 471 is aconstant region. The sequence of SEQ ID NO: 9, 10, 11 and 12 are shownin FIGS. 3, 4, 5 and 6 respectively. Further, in the light chain aminoacid sequence represented by SEQ ID NO: 13, 14, 15, 16, 17, 18 or 19 inthe Sequence Listing, an amino acid sequence consisting of amino acidresidues 1 to 20 is a signal sequence, an amino acid sequence consistingof amino acid residues 21 to 128 is a variable region, and an amino acidsequence consisting of amino acid residues 129 to 233 is a constantregion. The sequence of SEQ ID NO: 13, 14, 15, 16, 17, 18 and 19 areshown in FIGS. 7, 8, 9, 10, 11, 12 and 13 respectively.

Further, the antibody of the invention includes a human antibody whichbinds to the same epitope as the M30 antibody. An anti-B7-H3 humanantibody refers to a human antibody having only a sequence of anantibody derived from a human chromosome. The anti-B7-H3 human antibodycan be yielded by a method using a human antibody-producing mouse havinga human chromosome fragment comprising heavy and light chain genes of ahuman antibody (see Tomizuka, K. et al., Nature Genetics (1997) 16, pp.133-143; Kuroiwa, Y. et al., Nucl. Acids Res. (1998) 26, pp. 3447-3448;Yoshida, H. et al., Animal Cell Technology: Basic and Applied Aspectsvol. 10, pp. 69-73 (Kitagawa, Y., Matuda, T. and Iijima, S. eds.),Kluwer Academic Publishers, 1999; Tomizuka, K. et al., Proc. Natl. Acad.Sci. USA (2000) 97, pp. 722-727, etc.).

Such a human antibody-producing mouse can be created specifically asfollows. A genetically modified animal in which endogenousimmunoglobulin heavy and light chain gene loci have been disrupted, andinstead, human immunoglobulin heavy and light chain gene loci have beenintroduced via a yeast artificial chromosome (YAC) vector or the like iscreated by producing a knockout animal and a transgenic animal andmating these animals.

Further, according to a recombinant DNA technique, by using cDNAsencoding each of such a heavy chain and a light chain of a humanantibody, and preferably a vector comprising such cDNAs, eukaryoticcells are transformed, and a transformant cell which produces arecombinant human monoclonal antibody is cultured, whereby the antibodycan also be yielded from the culture supernatant.

Here, as the host, for example, eukaryotic cells, preferably mammaliancells such as CHO cells, lymphocytes, or myeloma cells can be used.

Further, a method of yielding a phage display-derived human antibodyselected from a human antibody library (see Wormstone, I. M. et al.,Investigative Ophthalmology & Visual Science. (2002) 43 (7), pp.2301-2308; Carmen, S. et al., Briefings in Functional Genomics andProteomics (2002), 1 (2), pp. 189-203; Siriwardena, D. et al.,Ophthalmology (2002) 109 (3), pp. 427-431, etc.) is also known.

For example, a phage display method in which a variable region of ahuman antibody is expressed on the surface of a phage as a single-chainantibody (scFv), and a phage which binds to an antigen is selected(Nature Biotechnology (2005), 23, (9), pp. 1105-1116) can be used.

By analyzing the gene of the phage selected based on the binding to anantigen, a DNA sequence encoding the variable region of a human antibodywhich binds to an antigen can be determined.

If the DNA sequence of scFv which binds to an antigen is determined, ahuman antibody can be yielded by preparing an expression vectorcomprising the sequence and introducing the vector into an appropriatehost to express it (WO 92/01047, WO 92/20791, WO 93/06213, WO 93/11236,WO 93/19172, WO 95/01438, WO 95/15388, Annu. Rev. Immunol. (1994) 12,pp. 433-455, Nature Biotechnology (2005) 23 (9), pp. 1105-1116).

If a newly produced human antibody binds to a partial peptide or apartial tertiary structure to which the M30 antibody binds, it can bedetermined that the human antibody binds to the same epitope as the M30antibody. Further, by confirming that the human antibody competes withthe M30 antibody for the binding to B7-H3 (that is, the human antibodyinhibits the binding between the M30 antibody and B7-H3), it can bedetermined that the human antibody binds to the same epitope as the M30antibody even if the specific epitope sequence or structure has not beendetermined. When it is confirmed that the human antibody binds to thesame epitope as the M30 antibody, the human antibody is stronglyexpected to have a cytotoxic activity equivalent to that of the M30antibody.

The chimeric antibodies, humanized antibodies, or human antibodiesyielded by the above-described method are evaluated for the bindingproperty to an antigen by a known method or the like, and a preferredantibody can be selected.

As one example of another index for use in the comparison of theproperties of antibodies, the stability of antibodies can beexemplified. The differential scanning calorimetry (DSC) is a devicecapable of quickly and accurately measuring a thermal denaturationmidpoint temperature (Tm) to be used as a favorable index of therelative conformational stability of proteins. By measuring the Tmvalues using DSC and comparing the values, a difference in thermalstability can be compared. It is known that the storage stability ofantibodies shows some correlation with the thermal stability ofantibodies (Lori Burton, et. al., Pharmaceutical Development andTechnology (2007) 12, pp. 265-273), and a preferred antibody can beselected by using thermal stability as an index. Examples of otherindices for selecting antibodies include the following features: theyield in an appropriate host cell is high; and the aggregability in anaqueous solution is low. For example, an antibody which shows thehighest yield does not always show the highest thermal stability, andtherefore, it is necessary to select an antibody most suitable for theadministration to humans by making comprehensive evaluation based on theabove-described indices.

In the invention, a modified variant of the antibody is also included.The modified variant refers to a variant yielded by subjecting theantibody of the invention to chemical or biological modification.Examples of the chemically modified variant include variants chemicallymodified by linking a chemical moiety to an amino acid skeleton,variants chemically modified with an N-linked or O-linked carbohydratechain, etc. Examples of the biologically modified variant includevariants yielded by post-translational modification (such as N-linked orO-linked glycosylation, N- or C-terminal processing, deamidation,isomerization of aspartic acid, or oxidation of methionine), andvariants in which a methionine residue has been added to the N terminusby being expressed in a prokaryotic host cell.

Further, an antibody labeled so as to enable the detection or isolationof the antibody or an antigen of the invention, for example, anenzyme-labeled antibody, a fluorescence-labeled antibody, and anaffinity-labeled antibody are also included in the meaning of themodified variant. Such a modified variant of the antibody of theinvention is useful for improving the stability and blood retention ofthe original antibody of the invention, reducing the antigenicitythereof, detecting or isolating such an antibody or an antigen, and soon.

Further, by regulating the modification of a glycan which is linked tothe antibody of the invention (glycosylation, defucosylation, etc.), itis possible to enhance an antibody-dependent cellular cytotoxicactivity. As the technique for regulating the modification of a glycanof antibodies, WO 99/54342, WO 00/61739, WO 02/31140, etc. are known.However, the technique is not limited thereto. In the antibody of theinvention, an antibody in which the modification of a glycan isregulated is also included.

In the case where an antibody is produced by first isolating an antibodygene and then introducing the gene into an appropriate host, acombination of an appropriate host and an appropriate expression vectorcan be used. Specific examples of the antibody gene include acombination of a gene encoding a heavy chain sequence of an antibodydescribed in this specification and a gene encoding a light chainsequence thereof. When a host cell is transformed, it is possible toinsert the heavy chain sequence gene and the light chain sequence geneinto the same expression vector, and also into different expressionvectors separately.

In the case where eukaryotic cells are used as the host, animal cells,plant cells, and eukaryotic microorganisms can be used. As the animalcells, mammalian cells, for example, simian COS cells (Gluzman, Y.,Cell, (1981) 23, pp. 175-182, ATCC CRL-1650), murine fibroblasts NIH3T3(ATCC No. CRL-1658), and dihydrofolate reductase-deficient strains(Urlaub, G. and Chasin, L. A., Proc. Natl. Acad. Sci. USA (1980) 77, pp.4126-4220) of Chinese hamster ovarian cells (CHO cells; ATCC: CCL-61)can be exemplified.

In the case where prokaryotic cells are used, for example, Escherichiacoli and Bacillus subtilis can be exemplified.

By introducing a desired antibody gene into these cells throughtransformation, and culturing the thus transformed cells in vitro, theantibody can be yielded. In the above-described culture method, theyield may sometimes vary depending on the sequence of the antibody, andtherefore, it is possible to select an antibody which is easily producedas a pharmaceutical by using the yield as an index among the antibodieshaving an equivalent binding activity. Therefore, in the antibody of theinvention, an antibody yielded by a method of producing an antibody,characterized by including a step of culturing the transformed host celland a step of collecting a desired antibody from a cultured productyielded in the culturing step is also included.

It is known that a lysine residue at the carboxyl terminus of the heavychain of an antibody produced in a cultured mammalian cell is deleted(Journal of Chromatography A, 705: 129-134 (1995)), and it is also knownthat two amino acid residues (glycine and lysine) at the carboxylterminus of the heavy chain of an antibody produced in a culturedmammalian cell are deleted and a proline residue newly located at thecarboxyl terminus is amidated (Analytical Biochemistry, 360: 75-83(2007)). However, such deletion and modification of the heavy chainsequence do not affect the antigen-binding affinity and the effectorfunction (the activation of a complement, the antibody-dependentcellular cytotoxicity, etc.) of the antibody. Therefore, in theinvention, an antibody subjected to such modification is also included,and a deletion variant in which one or two amino acids have been deletedat the carboxyl terminus of the heavy chain, a variant yielded byamidation of the deletion variant (for example, a heavy chain in whichthe carboxyl terminal proline residue has been amidated), and the likecan be exemplified. The type of deletion variant having a deletion atthe carboxyl terminus of the heavy chain of the antibody according tothe invention is not limited to the above variants as long as theantigen-binding affinity and the effector function are conserved. Thetwo heavy chains constituting the antibody according to the inventionmay be of one type selected from the group consisting of a full-lengthheavy chain and the above-described deletion variant, or may be of twotypes in combination selected therefrom. The ratio of the amount of eachdeletion variant can be affected by the type of cultured mammalian cellswhich produce the antibody according to the invention and the cultureconditions, however, a case where one amino acid residue at the carboxylterminus has been deleted in both of the two heavy chains contained asmain components in the antibody according to the invention can beexemplified.

As isotype of the antibody of the invention, for example, IgG (IgG1,IgG2, IgG3, IgG4) can be exemplified, and IgG1 or IgG2 can beexemplified preferably.

As the function of the antibody, generally an antigen-binding activity,an activity of neutralizing the activity of an antigen, an activity ofenhancing the activity of an antigen, an antibody-dependent cellularcytotoxicity (ADCC) activity and a complement-dependent cytotoxicity(CDC) activity can be exemplified. The function of the antibody of theinvention is a binding activity to B7-H3, preferably anantibody-dependent cell-mediated phagocytosis (ADCP) activity, morepreferably a cytotoxicity activity (antitumor activity) to tumor cellmediated by an ADCP activity. Further, the antibody of the invention mayhave an ADCC activity and/or a CDC activity in addition to an ADCPactivity.

The yielded antibody can be purified to homogeneity. The separation andpurification of the antibody may be performed employing a conventionalprotein separation and purification method. For example, the antibodycan be separated and purified by appropriately selecting and combiningcolumn chromatography, filter filtration, ultrafiltration, saltprecipitation, dialysis, preparative polyacrylamide gel electrophoresis,isoelectric focusing electrophoresis, and the like (Strategies forProtein Purification and Characterization: A Laboratory Course Manual,Daniel R. Marshak et al. eds., Cold Spring Harbor Laboratory Press(1996); Antibodies: A Laboratory Manual. Ed Harlow and David Lane, ColdSpring Harbor Laboratory (1988)), but the method is not limited thereto.

Examples of such chromatography include affinity chromatography, ionexchange chromatography, hydrophobic chromatography, gel filtrationchromatography, reverse phase chromatography, and adsorptionchromatography.

Such chromatography can be performed employing liquid chromatographysuch as HPLC or FPLC.

As a column to be used in affinity chromatography, a Protein A columnand a Protein G column can be exemplified. For example, as a columnusing a Protein A column, Hyper D, POROS, Sepharose FF (Pharmacia) andthe like can be exemplified.

Further, by using a carrier having an antigen immobilized thereon, theantibody can also be purified utilizing the binding property of theantibody to the antigen.

[Antitumor Compound]

The antitumor compound to be conjugated to the antibody-drug conjugateof the present invention is explained. The antitumor compound is notparticularly limited if it is a compound having an antitumor effect anda substituent group or a partial structure allowing connecting to alinker structure. When a part or whole linker is cleaved in tumor cells,the antitumor compound moiety is released to exhibit the antitumoreffect of the antitumor compound. As the linker is cleaved at aconnecting position to drug, the antitumor compound is released in itsintrinsic structure to exhibit its intrinsic antitumor effect.

Examples of the antitumor compound can include doxorubicin,daunorubicin, mitomycin C, bleomycin, cyclocytidine, vincristine,vinblastine, methotrexate, platinum-based antitumor agent (cisplatin orderivatives thereof), taxol or derivatives thereof, and camptothecin orderivatives thereof (antitumor agent described in Japanese PatentLaid-Open No. 6-87746). In the antibody-drug conjugate of the presentinvention, exatecan as a camptothecin derivative(((1S,9S)-1-amino-9-ethyl-5-fluoro-2,3-dihydro-9-hydroxy-4-methyl-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinoline-10,13(9H,15H)-dione;shown in the following formula) can be preferably used.

Although having an excellent antitumor effect, exatecan has not beencommercialized as an antitumor drug. The compound can be easily obtainedby a known method and the amino group at position 1 can be preferablyused as a connecting position to the linker structure. Further, althoughexatecan can be also released in tumor cells while part of the linker isstill attached thereto, it is an excellent compound exhibiting anexcellent antitumor effect even in such case.

With regard to the antibody-drug conjugate, the number of conjugateddrug molecules per antibody molecule is a key factor having an influenceon the efficacy and safety. Production of the antibody-drug conjugate isperformed by defining the reaction condition including the amounts ofuse of raw materials and reagents for reaction so as to have a constantnumber of conjugated drug molecules, a mixture containing differentnumbers of conjugated drug molecules is generally obtained unlike thechemical reaction of a low-molecular-weight compound. The number ofdrugs conjugated in an antibody molecule is expressed or specified bythe average value, that is, the average number of conjugated drugmolecules. Unless specifically described otherwise as a principle, thenumber of conjugated drug molecules means an average value except in acase in which it represents an antibody-drug conjugate having a specificnumber of conjugated drug molecules that is included in an antibody-drugconjugate mixture having different number of conjugated drug molecules.The number of exatecan molecules conjugated to an antibody molecule iscontrollable, and as an average number of conjugated drug molecules perantibody, about 1 to 10 exatecans can be bound. Preferably, it is 2 to8, and more preferably 3 to 8. Meanwhile, a person skilled in the artcan design a reaction for conjugating a required number of drugmolecules to an antibody molecule based on the description of theExamples of the present application and can obtain an antibodyconjugated with a controlled number of exatecan molecules.

Because exatecan has a camptothecin structure, it is known that theequilibrium shifts to a structure with a closed lactone ring (closedring) in an aqueous acidic medium (for example, pH 3 or so) but itshifts to a structure with an open lactone ring (open ring) in anaqueous basic medium (for example, pH 10 or so). A drug conjugate beingintroduced with an exatecan residue corresponding to the closed ringstructure and the open ring structure is also expected to have the sameantitumor effect and it is needless to say that any of them is withinthe scope of the present invention.

[Linker Structure] 1. Linker Having Hydrophilic Structure

The antibody-drug conjugate of the present invention is characterized bya linker structure in which a hydrophilic structure moiety is formed.This hydrophilic structure moiety is present in the L^(P) moiety, L¹moiety, or L² moiety of the linker and pleural of them may have thehydrophilic structure. This hydrophilic structure corresponds to thefollowing cases. In case of linker L^(P), either of the two followingforms corresponds to, i.e.,

L^(P) is a peptide residue having a hydrophilic amino acid other thanglycin at its N terminal, orL^(P) is a peptide residue in which the C terminal is an oligopeptideconsisting of 2 or 3 or more glycines and is connected to the drug, andfurther, even in case that a hydrophilic amino acid is present at Nterminal, no other hydrophilic amino acid than glycine is presentthereat, in case of L¹, L¹ corresponds to the form of-(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH-]—C(═O)—,in case of L², L² corresponds to the form of—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)—.

Hereinbelow, the linker of the present invention is described. Thelinker of the present invention has a structure represented by thefollowing formula:

-   -L¹-L²-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- or -L¹-L²-L^(P)-

The antibody is connected to the terminal of L¹, terminal opposite tothe connecting position to L². The antitumor drug is connected to theterminal of L^(c), terminal opposite to the connecting position toL^(b), or the terminal of L^(P), terminal opposite to the connectingposition to L².

n¹ represents an integer of 0 to 6 and is preferably an integer of 1 to5, and more preferably 1 to 3.

2. Hydrophilic Structure in L^(P)

The hydrophilic structure of each moiety in the linker is described. Asfor linker L^(P), two forms are present as the hydrophilic structure.One of them is a structure in which the peptide residue L^(P) is apeptide residue having a hydrophilic amino acid at its N terminal and,also, this N-terminal hydrophilic amino acid is a hydrophilic amino acidother than glycine.

The total number of amino acids constituting such a peptide linker canbe in a range of from 3 to 8. The hydrophilic amino acid other thanglycine can be aspartic acid, glutamic acid, lysine, serine, threonine,glutamine, asparagine, histidine, tyrosine, or arginine. Among them,glutamic acid, aspartic acid, or lysine is preferred, and aspartic acidis more preferred. The number of this hydrophilic amino acid can be 1 ormore and is preferably 1 or 2, and more preferably 1.

A peptide following this hydrophilic amino acid can be in a range offrom 2 to 7 in total and more preferably consists of 3 or 4 amino acids.This peptide can be a peptide consisting of amino acids selected fromphenylalanine (Phe; F), tyrosine (Tyr; Y), leucine (Leu; L), glycine(Gly; G), alanine (Ala; A), valine (Val; V), lysine (Lys; K), citrulline(Cit), serine (Ser; S), glutamic acid (Glu; E), aspartic acid (Asp; D),and the like. Further, the amino acids constituting the peptide can beany of L- and D-amino acids and are preferably L-amino acids. Further,the amino acids may be amino acids having a structure such as β-alanine,ε-aminocaproic acid, or γ-aminobutyric acid in addition to α-aminoacids. Further, they can be non-natural type amino acids such asN-methylated amino acids. Among them, preferred examples can includephenylalanine, glycine, valine, lysine, citrulline, serine, glutamicacid, and aspartic acid. The peptide after the second amino acid countedfrom the N terminal in the peptide residue of the linker is preferablyGGF or GGFG.

The peptide residue L^(P) of the linker having a hydrophilic amino acidat the N terminal is preferably DGGF, KGGF, EGGF, DGGFG, KGGFG, orEGGFG, more preferably DGGF, KGGF, DGGFG, or KGGFG, and furtherpreferably DGGF or DGGFG.

Another form in which L^(P) becomes a hydrophilic linker can include acase in which the C terminal is an oligopeptide consisting of 2 or 3 ormore glycines and is connected to the drug, and also, even in case thata hydrophilic amino acid is present at N terminal, no other hydrophilicamino acid than glycine is present thereat. Although glycine is alsoclassified as a hydrophilic amino acid, it is preferable that aplurality of glycines are connected to the C terminal when glycine isselected as the hydrophilic amino acid in the peptide linker. Such aglycine oligopeptide can consist of 2 or 3 or more glycines and ispreferably glycine di- or tri-peptide.

When linker L^(P) has the hydrophilic structure containing the glycineoligopeptide, preferred examples thereof can include GGFGG and GGFGGG.

Also, when L^(P) has the hydrophilic structure containing the glycineoligopeptide at the C terminal, a further feature of this peptideresidue of the linker is that L^(P) having this structure is directlyconnected to the drug.

When oligopeptide consisting of 2 or 3 or more glycines is present atthe C terminal and is connected to the drug, a peptide sequence otherthan this moiety in the peptide linker L^(P) can be a peptide consistingof amino acids selected from phenylalanine, glycine, valine, lysine,citrulline, serine, glutamic acid, and aspartic acid. However, in thiscase, the N terminal of the peptide residue of the linker is notaspartic acid, glutamic acid, lysine, serine, threonine, glutamine,asparagine, histidine, tyrosine, or arginine listed above as thehydrophilic amino acid.

The amino acids constituting the peptide can be any of L- and D-aminoacids and are preferably L-amino acids. Further, the amino acids may beamino acids having a structure such as β-alanine, ε-aminocaproic acid,or γ-aminobutyric acid in addition to α-amino acids. Further, they canbe non-natural type amino acids such as N-methylated amino acids. As forthe number of the amino acids, the peptide can consist of 4 to 8 aminoacids and more preferably consists of 4 to 6 amino acids.

3. L^(P)

The liner L^(P) may be in a form that does not have the hydrophilicstructure, as mentioned below. Specifically, even when linker L^(P) doesnot have the hydrophilic structure, linker L^(P) can consist of anoligopeptide residue in which 3 to 8 amino acids are linked by a peptidebonding. L^(P) is connected to L² at its N terminal and is connected tothe —NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- moiety of the linker at its Cterminal or directly to the antitumor compound at its C terminal, incase of exatecan, it is connected to the amino group at position 1thereof.

The amino acid constituting L^(P) that does not have the hydrophiliclinker is not particularly limited as long as it is not the amino acidconstituting L^(P) having the hydrophilic structure. The amino acid canbe any of L- and D-amino acids and is preferably an L-amino acid.Further, it can be an amino acid having a structure such as β-alanine,ε-aminocaproic acid, or γ-aminobutyric acid in addition to an α-aminoacid. Further, it can be a non-natural type amino acid such asN-methylated amino acid.

The amino acid sequence of such L^(P) is not particularly limited, butexamples of the constituting amino acid can include phenylalanine,tyrosine, leucine, glycine, alanine, valine, lysine, citrulline, serine,glutamic acid, and aspartic acid. Among them, preferred examples caninclude phenylalanine, glycine, valine, lysine, citrulline, serine,glutamic acid, and aspartic acid. Depending on the type of the aminoacid, drug release pattern can be controlled. The number of the aminoacid can be between 3 to 8.

Specific examples of L^(P) that does not form the hydrophilic structurein the linker can include

-   -GGF--   -GGFG--   -GFLG-.

Among them, -GGF- or -GGFG- can be preferably used.

In the structure moiety represented by —NH—(CH₂)n¹- in the linker, n¹ isan integer of 0 to 6 and is preferably an integer of 1 to 5, and morepreferably 1 to 3. The amino group of this moiety is connected to the Cterminal of L^(P).

4. Hydrophilic Structure in L¹ or L²

When linker L¹ takes a form of-(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—, this moiety correspondsto the hydrophilic linker according to the present invention. n³ is aninteger of 1 to 8 and is preferably 2 to 4, and more preferably 2. In—(CH₂)n³-COOH of this hydrophilic structure moiety, the carboxy groupmay be a hydroxy group or an amino group. When L¹ in the linker is-(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—, L² in the linker is—NH—(CH₂—CH₂—O)n⁶-CH₂—CH₂—C(═O)— wherein n⁶ is 0 to 4, preferably.

When linker L² takes a form of —N[—(CH₂CH₂—O) n⁷-CH₂CH₂—OH]-CH₂—C(═O)—,this moiety corresponds to the hydrophilic structure according to thepresent invention. n⁷ is an integer of 1 to 4 and is preferably 3 or 4.This linker is connected to L¹ at its terminal amino group and isconnected to the N terminal of L^(P) at its carbonyl group at the otherterminal.

The presence of the linker having the hydrophilic structure describedabove can achieve the excellent release of the drug component having anantitumor effect.

5. L¹

The linker L¹ is the linker represented by the following structure of-(Succinimid-3-yl-N)—(CH₂)n²-C(═O)—,-(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—,—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—,—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-, or —C(═O)—(CH₂)n⁵-C(═O)—.Wherein, n² is an integer of 2 to 8, n³ is an integer of 1 to 8, and n⁴is an integer of 1 to 8, and n⁵ is an integer of 1 to 8.

In the linker having a structure represented by

-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-m among L¹,    “-(Succinimid-3-yl-N)-” has a structure represented by the following    formula:

Position 3 of the above partial structure is a connecting position tothe antibody. And further, the bond to the antibody at this position 3is characterized by connecting with the formation of thioether at adisulfide bond moiety in a hinge part of the antibody. On the otherhand, the nitrogen atom at position 1 of this structure moiety isconnected to the carbon atom of methylene which is present within thelinker including this structure. Specifically,-(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-L²- is a structure represented by thefollowing formula (herein, “antibody-S-” originates from an antibody).

In the formula, n² is an integer of 2 to 8, and preferably 2 to 5.

Among L¹, -(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)— is thehydrophilic structure mentioned above.

In the linker having a structure represented by—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)— among L¹, n⁴ is an integer of 1 to 8,preferably 2 to 6. This linker is connected to the antibody at itscarbon atom of terminal methylene and, as with the preceding, has thefollowing structure for connection by forming thioether, (herein,“antibody-S-” originates from an antibody).

Antibody-S—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-L²-.

In the linker having a structure represented by—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)- among L¹,“—(N-ly-3-diminiccuS)-” has a structure represented by the followingformula:

In this structure moiety, the nitrogen atom at position 1 is connectedto the carbon atom of methylene present in the linker structurecontaining this structure. The carbon atom at position 3 is connected to—S—(CH₂)n⁸-C(═O)— among linker L² at its terminal sulfur atom. This—S—(CH₂)n⁸-C(═O)— among linker L² forms a linker structure only combinedwith —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)- among linker L¹. Inthe above, “-cyc.Hex(1,4)-” contained in the linker represents a1,4-cyclohexylene group. The linker—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)- is connected to theantibody by forming amide bond at its terminal carbonyl carbon (herein,“antibody-NH-” originates from an antibody).

The amino group of the antibody forming this amide bond may be an aminogroup in a lysine residue in the antibody or that at the N terminal ofthe antibody. The linker can be connected by amide bond as well as withester bond formation with the hydroxy group carried by an amino acid inthe antibody.

The structure moiety “-cyc.Hex(1,4)-” in the linker may be a divalentsaturated cyclic alkylene group other than the 1,4-cyclohexylene group,i.e., a divalent cyclic saturated hydrocarbon group such as acyclobutylene group, a cyclopentylene group, a cycloheptalene group, ora cyclooctalene group. The moiety may also be a divalent aromatichydrocarbon group such as a phenylene group or a naphthylene group, or a5- or 6-membered saturated, partially saturated, or aromatic divalentheterocyclic group containing 1 or 2 heteroatoms. Alternatively, thismoiety may be a divalent alkylene group having 1 to 4 carbon atoms. Thedivalent group may be at adjacent positions or at distant positions.

In the linker having a structure represented by —C(═O)—(CH₂)n⁵-C(═O)—among L¹, n⁵ is an integer of 1 to 8, and preferably 2 to 6. This linkeris also connected by forming amide bond at its terminal carbonyl groupwith an amino group of an amino acid in the antibody, as with the linkermentioned above (see the following formula; in the structure thereof,“antibody-NH-” originates from an antibody).

Antibody-NH—C(═O)—(CH₂)n⁵-C(═O)-L²-.

Specific examples of L¹ in the linker can include

-   -(Succinimid-3-yl-N)—CH₂CH₂—C(═O)--   -(Succinimid-3-yl-N)—CH₂CH₂CH₂—C(═O)--   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂—C(═O)--   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)--   -(Succinimid-3-yl-N)—CH(—CH₂—COOH)—C(═O)--   -(Succinimid-3-yl-N)—CH(—CH₂CH₂—COOH)—C(═O)--   -(Succinimid-3-yl-N)—CH(—CH₂CH₂CH₂—COOH)—C(═O)--   -(Succinimid-3-yl-N)—CH(—CH₂CH₂CH₂CH₂—COOH)—C(═O)--   -(Succinimid-3-yl-N)—CH(—CH₂CH₂CH₂CH₂CH₂—COOH)—C(═O)--   -(Succinimid-3-yl-N)—CH(—CH₂CH₂CH₂CH₂CH₂CH₂—COOH)—C(═O)--   -(Succinimid-3-yl-N)—CH(—CH₂CH₂CH₂CH₂CH₂CH₂CH₂—COOH)—C(═O)--   -(Succinimid-3-yl-N)—CH(—CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂—COOH)—C(═O)--   —CH₂—C(═O)—NH—CH₂—C(═O)--   —CH₂—C(═O) NH—CH₂CH₂—C(═O)--   —CH₂—C(═O) NH—CH₂CH₂CH₂—C(═O)--   —CH₂—C(═O) NH—CH₂CH₂CH₂CH₂—C(═O)--   —CH₂—C(═O) NH—CH₂CH₂CH₂CH₂CH₂—C(═O)--   —C(═O)-cyc.Hex (1,4)-CH₂—(N-ly-3-diminiccuS)--   —C(═O)-Aryl-CH₂—(N-ly-3-diminiccuS)--   —C(═O)-cyc.Het-CH₂—(N-ly-3-diminiccuS)--   —C(═O)—CH₂—C(═O)--   —C(═O)—CH₂CH₂—C(═O)--   —C(—O)—CH₂CH₂CH₂—C(—O)—-   —C(—O)—CH₂CH₂CH₂CH₂—C(—O)—-   —C(—O)—CH₂CH₂CH₂CH₂CH₂—C(—O)--   —C(—O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—.    (Aryl represents a divalent aromatic hydrocarbon group, and cyc.Het    represents a divalent cyclic heterocyclic group).

6. L²

Linker L² is a linker represented by the following structure:—NH—(CH₂—CH₂—O) n⁶-CH₂—CH₂—C(═O)—,—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)—, or —S—(CH₂)n⁸-C(═O)—, L² may notbe present, and in such a case, L² is a single bond. And, n⁶ is aninteger of 0 to 6, n⁷ is an integer of 1 to 4, and n⁸ is an integer of 1to 6.

In the linker having a structure represented by—NH—(CH₂CH₂O)n⁶-CH₂—CH₂—C(═O)- among L², n⁶ is an integer of 0 to 6, andpreferably 2 to 4. Said linker is connected to L¹ at the nitrogen atomof its terminal amino group and is connected to the N terminal of L^(P)at its carbonyl group at the other terminal. When L¹ is-(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—, only —NH—(CH₂CH₂O)n⁶-CH₂—CH₂—C(═O)- wintin L² is connected to this and also n⁶ is 0.

Among L², the linker represented by—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—(C(═O)— is the hydrophilic structurepreviously mentioned.

In the linker having a structure represented by —S—(CH₂)n⁸-C(═O)— amongL², n⁸ is an integer of 1 to 6, and preferably 2 to 4.

Specific examples of L² in the linker can include

-   —NH—CH₂CH₂—C(═O)--   —NH—CH₂CH₂O—CH₂CH₂—C(═O)--   —NH—CH₂CH₂O—CH₂CH₂O—CH₂CH₂—C(═O)--   —NH—CH₂CH₂O—CH₂CH₂O—CH₂CH₂O—CH₂CH₂—C(═O)—-   —NH—CH₂CH₂O—CH₂CH₂O—CH₂CH₂O—CH₂CH₂O—CH₂CH₂—C(═O)—-   —NH—CH₂CH₂O—CH₂CH₂O—CH₂CH₂O—CH₂CH₂O—CH₂CH₂O—CH₂CH₂—C(═O)--   —NH—CH₂CH₂O—CH₂CH₂O—CH₂CH₂O—CH₂CH₂O—CH₂CH₂O—CH₂CH₂O—CH₂CH₂—C(═O)--   —N(—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)--   —N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)--   —N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)--   —N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)—.

When L² is —S—(CH₂)n⁸⁻C(═O)—, L¹ to be combined therewith is—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-. So the specific examplesof -L¹-L²- in the linker can include

-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂—C(═O)--   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)--   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂CH₂—C(═O)--   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂CH₂CH₂—C(—O)--   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂CH₂CH₂CH₂—C(—O)--   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂CH₂CH₂CH₂CH₂—C(—O)—.

7. L^(a)

The linker L^(a) is any of structures —C(═O)—NH—, —NR¹—(CH₂)n⁹-, and —O—or is a single bond, wherein, n⁹ is an integer of 1 to 6, R¹ is ahydrogen atom, an alkyl group having 1 to 6 carbon atoms,—(CH₂)n^(a)-COOH, or —(CH₂)n^(b)-OH, n^(a) is an integer of 1 to 4, andn^(b) is an integer of 1 to 6.

The amide structure —C(═O)—NH— among linker L^(a) is connected to L^(b)at its nitrogen atom side. In the structure moiety —NR¹—(CH₂)n⁹- amonglinker L^(a), n⁹ is an integer of 1 to 6, and preferably 1 to 3. Thismoiety is connected to L^(b) at its methylene side. R¹ is a hydrogenatom or an alkyl group having 1 to 6 carbon atoms. The alkyl grouphaving 1 to 6 carbon atoms may be linear or branched. Examples thereofcan include a methyl group, an ethyl group, a propyl group, an isopropylgroup, a butyl group, an isobutyl group, a sec-butyl group, a tert-butylgroup, a pentyl group, an isopentyl group, a 2-methylbutyl group, aneopentyl group, a 1-ethylpropyl group, a hexyl group, an isohexylgroup, a 4-methylpentyl group, a 3-methylpentyl group, a 2-methylpentylgroup, a 1-methylpentyl group, a 3,3-dimethylbutyl group, a2,2-dimethylbutyl group, a 1,1-dimethylbutyl group, a 1,2-dimethylbutylgroup, a 1,3-dimethylbutyl group, a 2,3-dimethylbutyl group, and a2-ethylbutyl group. Of them, a methyl group or an ethyl group ispreferred. When R¹ has a structure represented by —(CH₂)n^(a)-COOH,n^(a) is an integer of 1 to 4, and preferably 1 or 2. When R¹ has astructure represented by —(CH₂)n^(b)-OH, n⁹ is an integer of 1 to 6, andpreferably 1 or 2. R¹ is preferably a hydrogen atom, a methyl group, anethyl group, —CH₂COOH, —CH₂CH₂—COOH, or —CH₂CH₂—OH, and more preferablya hydrogen atom, a methyl group, or —CH₂COOH. It is further preferably ahydrogen atom. The L^(a) moiety of the linker may be —O— or a singlebond.

8. L^(b)

The linker L^(b) is any of structures —CR²(—R³)—, —O—, and —NR⁴— or is asingle bond. In the above, R² and R³ each independently represents ahydrogen atom, an alkyl group having 1 to 6 carbon atoms,—(CH₂)n^(c)-NH₂, —(CH₂)n^(d)-COOH, or —(CH₂)n^(e)-OH, R⁴ is a hydrogenatom or an alkyl group having 1 to 6 carbon atoms, n^(c) is an integerof 0 to 6, n^(d) is an integer of 1 to 4, and n^(e) is an integer of 0to 4. When n^(c) or n^(e) is 0, R² and R³ are not the same as eachother.

When each of R² and R³ is an alkyl group, this alkyl group isinterpreted as defined in the alkyl group of R¹. When each of R² and R³has a structure of —(CH₂)n^(c)-NH₂, n^(c) is an integer of 0 to 6, andpreferably 0, or is 3 to 5. When n^(c) is 0, R² and R³ are not the sameas each other. When each of R² and R³ has a structure of—(CH₂)n^(d)-COOH, n^(d) is an integer of 1 to 4, and preferably 1 or 2.When each of R² and R³ has a structure of —(CH₂)n^(e)-OH, n^(e) is aninteger of 0 to 4, and preferably 1 or 2.

Each of R² and R³ is preferably a hydrogen atom, a methyl group, anethyl group, —NH₂, —CH₂CH₂CH₂NH₂, —CH₂CH₂CH₂CH₂NH₂,—CH₂CH₂CH₂CH₂CH₂CH₂NH₂, —CH₂COOH, —CH₂CH₂—COOH, —CH₂OH, or —CH₂CH₂—OH,and more preferably a hydrogen atom, a methyl group, —NH₂,—CH₂CH₂CH₂CH₂NH₂, —CH₂COOH, —CH₂CH₂—COOH, —CH₂OH, or —CH₂CH₂—OH. Theyare further preferably hydrogen atoms.

When R⁴ is an alkyl group having 1 to 6 carbon atoms, this alkyl groupis interpreted as defined in the alkyl group of R¹. R⁴ is preferably ahydrogen atom or a methyl group, and more preferably a hydrogen atom.

Specific examples of the structure represented by linker—NH—(CH₂)n¹-L^(a)-L^(b)- include

-   —NH—CH₂—-   —NH—CH(-Me)--   —NH—C(-Me)₂--   —NH—CH₂—CHMe--   —NH—CH(—CH₂OH)--   —NH—CH(—CH₂COOH) --   —NH—CH(—CH₂CH₂COOH) --   —NH—CH(—CH₂CH₂CH₂CH₂NH₂)—-   —NH—CH₂CH₂—-   —NH—CH₂—O—CH₂—-   —NH—CH₂CH₂—O—-   —NH—CH₂CH₂—O—CH₂—-   —NH—CH₂CH₂C(-Me)₂--   —NH—CH₂CH₂NH—-   —NH—CH₂CH₂NH—CH₂—-   —NH—CH₂CH₂NMe-CH₂—-   —NH—CH₂CH₂NH—CH₂CH₂—-   —NH—CH₂CH₂NMe-CH₂CH₂—-   —NH—CH₂CH₂N(—CH₂COOH)—CH₂—-   —NH—CH₂CH₂N(—CH₂CH₂OH)—CH₂—-   —NH—CH₂CH₂N(—CH₂CH₂OH)—CH₂CH₂—-   —NH—CH₂CH₂CH₂C(═O)—NHCH(—CH₂OH) --   —NH—CH₂CH₂CH₂C(═O)—NHCH(—CH₂COOH) --   —NH—CH₂CH₂CH₂C(═O)—NHCH(—CH₂CH₂CH₂CH₂NH₂)—-   —NH—CH₂CH₂CH₂—-   -NH—CH₂CH₂CH₂CH₂—-   -NH—CH₂CH₂CH₂CH₂CH₂—-   -NH—CH₂CH₂CH₂CH₂CH(NH₂)—.

Of them, preferred examples thereof can include

-   —NH—CH₂—-   —NH—CH₂—CH(Me) --   —NH—CH(—CH₂OH) --   —NH—CH(—CH₂CH₂COOH) --   —NH—CH₂CH₂—-   —NH—CH₂—O—CH₂—-   —NH—CH₂CH₂—O—-   —NH—CH₂CH₂—O—CH₂—-   —NH—CH₂CH₂C(-Me)₂--   —NH—CH₂CH₂NH—-   —NH—CH₂CH₂NH—CH₂—-   —NH—CH₂CH₂NMe-CH₂—-   —NH—CH₂CH₂NMe-CH₂CH₂—-   —NH—CH₂CH₂N(—CH₂COOH)—CH₂—-   —NH—CH₂CH₂N(—CH₂CH₂OH)—CH₂—-   —NH—CH₂CH₂N(—CH₂CH₂OH)—CH₂CH₂—-   —NH—CH₂CH₂CH₂C(═O)—NHCH(—CH₂OH) --   —NH—CH₂CH₂CH₂C(═O)—NHCH(—CH₂COOH) --   —NH—CH₂CH₂CH₂—-   —NH—CH₂CH₂CH₂CH₂—-   —NH—CH₂CH₂CH₂CH₂CH₂—.

More preferred examples thereof can include

-   —NH—CH₂—-   —NH—CH₂CH₂—-   —NH—CH₂—O—CH₂—-   —NH—CH₂CH₂—O—-   —NH—CH₂CH₂—O—CH₂—-   —NH—CH₂CH₂NH—-   —NH—CH₂CH₂NH—CH₂—-   —NH—CH₂CH₂N(—CH₂COOH)—CH₂—-   —NH—CH₂CH₂N(—CH₂CH₂OH)—CH₂CH₂—-   —NH—CH₂CH₂CH₂C(═O)—NHCH(—CH₂COOH) --   —NH—CH₂CH₂CH₂—-   —NH—CH₂CH₂CH₂CH₂—-   —NH—CH₂CH₂CH₂CH₂CH₂—.

Further preferred examples thereof can include

-   —NH—CH₂—-   —NH—(CH₂)₂—-   —NH—(CH₂)₃—-   —NH—CH₂—O—CH₂— and-   —NH—(CH₂)₂—O—CH₂—.

9. L^(c)

The linker L^(c) is —CH₂— or —C(═O)—. Said linker is connected to theantitumor compound. The linker L^(c) is more preferably —C(═O)—.

The chain length of the linker —NH—(CH₂)n¹-L^(a)-L^(b)-L^(c) moiety ispreferably a chain length of 4 to 7 atoms, and more preferably a chainlength of 5 or 6 atoms.

With regard to the antibody-drug conjugate of the present invention,when it is transferred to the inside of tumor cells, the linker moietyis cleaved and the drug derivative having a structure represented byNH₂—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX) is released to express anantitumor activity. Examples of the antitumor derivative exhibiting anantitumor effect by releasing from the antibody-drug conjugate of thepresent invention include an antitumor derivative having a structuremoiety in which the structure represented by —NH—(CH₂)n¹-L^(a)-L^(b)- ofthe linker is bound with L^(c) and has a terminal amino group, and theparticularly preferred include the followings.

-   NH₂—CH₂—C(═O)-(NH-DX)-   NH₂—CH₂CH₂—C(═O)-(NH-DX)-   NH₂—CH₂CH₂CH₂—C(═O)-(NH-DX)-   NH₂—CH₂—O—CH₂—C(═O)-(NH-DX)-   NH₂—CHCH₂—O—CH₂—C(═O)-(NH-DX)

Meanwhile, in case of NH₂—CH₂—O—CH₂—C(═O)—(NH-DX), as the aminalstructure in the molecule is unstable, it again undergoes aself-decomposition to release the following

HO—CH₂—C(═O)—(NH-DX). Those compounds can be also preferably used as aproduction intermediate of the antibody-drug conjugate of the presentinvention.

For the antibody-drug conjugate of the present invention in whichexatecan is used as a drug, it is preferable that the drug-linkerstructure moiety having the structure described below is connected to anantibody. The average connected number of the drug-linker structuremoiety per antibody can be 1 to 10. Preferably, it is 2 to 8, and morepreferably 3 to 8. Preferred examples of the drug-linker structuremoiety can include the followings.

10. Specific Example when L^(P) has Hydrophilic Structure

A drug-linker structure moiety in which L^(P) is a peptide residuehaving a hydrophilic amino acid at the N terminal is present in the formof -L¹-L²-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX) or-L¹-L²-L^(P)-(NH-DX). The combinations of each part of the linkersconstituting this drug-linker structure moiety are the followings.

When the drug-linker structure moiety is connected to the antibody via athioether bond, L¹ is -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)— or—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—. When the drug-linker structure moiety isconnected to the antibody via an amide bond, it is—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)- or —C(═O)—(CH₂)n⁵-C(═O)—.

As for the linker L², when L¹ is -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)— or—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—, this can be a single bond, when linker L¹is —C(═O)—(CH₂)n⁵-C(═O)—, this is selected from —NH—(CH₂—CH₂—O)n⁶-CH₂—CH₂—C(═O)- and a single bond. And the linker —S—(CH₂)n⁸-C(═O)— isused in combination with —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-among L¹.

The linker —NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- moiety preferably has a chainlength of 3 to 7 atoms. The moiety more preferably has a chain length of4 to 7 atoms in the linker and further preferably has a chain length of5 or 6 atoms. Specific examples of the linker —NH—(CH₂)n¹-L^(a)-L^(b)-are as described above, —NH—CH₂CH₂—C(═O)—, —NH—CH₂CH₂CH₂—C(═O)—,—NH—CH₂—O—CH₂—C(═O)—, or —NH—CH₂CH₂—O—CH₂—C(═O)— is particularlypreferred one.

The linker -L^(c)- moiety is preferably —C(═O)—.

Specific examples of the drug-linker structure moiety containing thepeptide having a hydrophilic amino acid at the N terminal can includethe followings.

Examples of the drug-linker structure moiety for conjugating thedrug-linker structure moiety to the antibody via a thioether bond caninclude the following formulas:

-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-DGGF-NH—(CH₂)n¹-L^(c)-(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)—KGGF-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-EGGF-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-DGGFG-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)—KGGFG-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-EGGFG-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)

In the above formula, preferably, n² is 2 to 5, and the—NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- L moiety is —NH—CH₂CH₂—C(═O)—,—NH—CH₂CH₂CH₂—C(═O)—, —NH—CH₂—O—CH₂—C(═O)—, or —NH—CH₂CH₂—O—CH₂—C(═O)—.Also, those which L^(P) is directly connectred to the drug arepreferable.

More specifically, it is preferably represented by the followingformula:

-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-DGGF—NH—CH₂CH₂—C(═O)—(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-DGGF—NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-DGGF—NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-KGGF—NH—CH₂CH₂—C(═O)—(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-KGGF—NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-KGGF—NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-KGGF—NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-DGGFG-NH—CH₂CH₂—C(═O)—(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-KGGFG-NH—CH₂CH₂—C(═O)—(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-KGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-KGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)    or the following formulas:-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-DGGF-(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-KGGF-(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-DGGFG-(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-KGGFG-(NH-DX) More preferably, n²    is 2 or 5.

Further preferably, n² is 5, and it is represented by the followingformulas:

-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGF—NH—CH₂CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGF—NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGF—NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)    or the following formulas:-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGF-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGFG-(NH-DX)

Among them, it is further preferably represented by the followingformulas:

-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)    or the following formulas:-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-(NH-DX)

Examples of another form of the drug-linker structure moiety forconjugating the drug-linker structure moiety to the antibody via athioether bond can include the following formulas:

-   —CH—C(═O)—NH—(CH₂)n⁴-C(═O)-DGGF-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   —CH—C(═O)—NH—(CH₂)n⁴-C(═O)-KGGF-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   —CH—C(═O)—NH—(CH₂)n⁴-C(═O)-EGGF-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   —CH—C(═O)—NH—(CH₂)n⁴-C(═O)-DGGFG-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   —CH—C(═O)—NH—(CH₂)n⁴-C(═O)-KGGFG-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   —CH—C(═O)—NH—(CH₂)n⁴-C(═O)-EGGFG-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)

In the above formula, preferably, n⁴ is 2 to 5, and the —NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- moiety is —NH—CH₂CH₂—C(═O)—, —NH—CH₂CH₂CH₂—C(═O)—,—NH—CH₂—O—CH₂—C(═O)—, or —NH—CH₂CH₂—O—CH₂—C(═O)—. Also, those whichL^(P) is directly connected to the drug are preferable.

More specifically, it is preferably

-   —CH—C(═O)—NH—(CH₂)n⁴-C(═O)-DGGF-NH—CH₂CH₂—C(═O)-(NH-DX)-   —CH—C(═O)—NH—(CH₂)n⁴-C(═O)-DGGF-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   —CH—C(═O)—NH—(CH₂)n⁴-C(═O)-DGGF-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   —CH—C(═O)—NH—(CH₂)n⁴-C(═O)-DGGF-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   —CH—C(═O)—NH—(CH₂)n⁴-C(═O)—KGGF-NH—CH₂CH₂—C(═O)-(NH-DX)-   —CH—C(═O)—NH—(CH₂)n⁴-C(═O)—KGGF-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—KGGF-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—KGGF-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-DGGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX)-   —CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—KGGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—KGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—KGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX)    or the following formulas:-   —CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-DGGF-(NH-DX)-   —CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-KGGF-(NH-DX)-   —CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-DGGFG-(NH-DX)-   —CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-KGGFG-NH—(NH-DX)

More preferably, n⁴ is 2, and it is represented by

-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGF-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)    or the following formulas:-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-KGGF-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-KGGFG-(NH-DX)

Further preferably, it is

-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF—NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)    or the following formulas:-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-(NH-DX)

Alternatively, examples of the drug-linker structure moiety forconjugating the drug-linker structure moiety to the antibody via anamide bond can include the following formulas:

-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—(CH₂)n⁸-C(═O)-DGGF-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—(CH₂)n⁸-C(═O)-KGGF-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—(CH₂)n⁸-C(═O)-EGGF-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—(CH₂)n⁸-C(═O)-DGGFG-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—(CH₂)n⁸-C(═O)—KGGFG-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—(CH₂)n⁸-C(═O)-EGGFG-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)

In the above formula, n⁸ is preferably 1 to 6, and more preferably 2.The —NH—(CH₂)n¹-L^(a)-L^(b)-L^(c) moiety is preferably—NH—CH₂CH₂—C(═O)—, —NH—CH₂CH₂CH₂—C(═O)—, —NH—CH₂—O—CH₂—C(═O)—, or—NH—CH₂CH₂—O—CH₂—C(═O)—. Also, those which L^(P) is directly connectedto the drug are preferable.

More specifically, it is more preferably

-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—C(═O)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGF—NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-KGGF—NH—CH₂CH₂—C(═O)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-KGGF—NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-KGGF—NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-KGGF—NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-KGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)    or the following formulas:-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGF-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-KGGF-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-KGGFG-(NH-DX)

Among them, it is further preferably represented by the followingformula:

-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGF—NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)    or the following formulas:-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGF-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-(NH-DX)

Examples of another form of the drug-linker structure moiety forconjugating the drug-linker structure moiety to the antibody via anamide bond can include the following formulas:

-   —C(═O)—(CH₂)n⁵-C(═O)-L²-DGGF-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   —C(═O)—(CH₂)n⁵-C(═O)-L²-KGGF-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   —C(═O)—(CH₂)n⁵-C(═O)-L²-EGGF-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   —C(═O)—(CH₂)n⁵-C(═O)-L²-DGGFG-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   —C(═O)—(CH₂)n⁵-C(═O)-L²-KGGFG-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   —C(═O)—(CH₂)n⁵-C(═O)-L²-EGGFG-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)

In the above formula, n⁵ is preferably 6, and L² is —NH—(CH₂—CH₂—O)n⁶-CH₂—CH₂—C(═O)— or a single bond and is preferably a single bond. n⁶is preferably 0, 2, or 4, and more preferably 0. The—NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- moiety is preferably —NH—CH₂CH₂—C(═O)—,—NH—CH₂CH₂CH₂—C(═O)—, —NH—CH₂—O—CH₂—C(═O)—, or —NH—CH₂CH₂—O—CH₂—C(═O)—.Also, those which L^(P) is directly connected to the drug arepreferable.

More specifically, it is preferably

-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—C(═O)—(NH-DX)-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂—O—CH₂—C(═O)—(NH-DX)-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX)-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF—NH—CH₂CH₂—C(═O)—(NH-DX)-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGF—NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGF—NH—CH₂—O—CH₂—C(═O)—(NH-DX)-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGF—NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX)-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—C(═O)—(NH-DX)-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX)-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX)-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX)-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX)-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX)-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX)    or the following formulas:-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF-(NH-DX)-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGF-(NH-DX)-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-(NH-DX)-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGFG-(NH-DX)

When the linker L^(P) is a peptide residue having a glycine oligopeptideat the C terminal, the drug-linker structure moiety is present in a formin which L^(P) is directly connected to the drug, as in-L^(P)-L²-L^(P)-(NH-DX). When L^(P) in the linker is a peptide residuehaving a glycine oligopeptide at the C terminal, the combinations ofeach linker moiety constituting the drug-linker structure moiety are asfollows.

When the drug-linker structure moiety is connected to the antibody via athioether bond, the linker L¹ is -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)— or—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)— and when the drug-linker structure moietyis connected to the antibody via an amide bond, is selected from—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)- or —C(═O)—(CH₂)n⁵-C(═O)—.

As for the linker L², when linker L¹ is-(Succinimid-3-yl-N)—(CH₂)n²-C(═O)— or —CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—, itcan be —NH—(CH₂—CH₂—O) n⁶-CH₂—CH₂—C(═O)— or a single bond, and whenlinker L¹ in —C(═O)—(CH₂)n⁵-C(═O)—, it is selected from single bonds.And the linker —S—(CH₂)n⁸-C(═O)— is used in combination with—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)- among L¹.

Specific examples of the drug-linker structure moiety containing thepeptide having a glycine oligopeptide at the C terminal can include thefollowings.

Examples of the drug-linker structure moiety for conjugating thedrug-linker structure moiety to the antibody via a thioether bond caninclude following formulas:

-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-GGFGG-(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)-GGFGGG-(NH-DX)

In the above formula, preferably, n² is 2 or 5.

More preferably, n² is 5, and it is represented by the followingformula:

-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-GGFGG-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-GGFGGG-(NH-DX)

Examples of the drug-linker structure moiety in another form forconjugating the drug-linker structure moiety to the antibody via athioether bond can include the following formulas:

-   —CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-GGFGG-(NH-DX)-   —CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-GGFGGG-(NH-DX)

In the above formula, more preferably, n⁴ is 2 or 5.

Among them, more preferably, n⁴ is 2, and it is preferably representedby the following formula:

-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-GGFGG-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)-GGFGGG-(NH-DX)

Alternatively, examples of the drug-linker structure moiety forconjugating the drug-linker structure moiety to the antibody via anamide bond or an ester bond can include the following formulas:

-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—(CH₂)n⁸-C(═O)-GGFGG-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—(CH₂)n⁸-C(═O)-GGFGGG-(NH-DX)

In the above formula, n⁸ is preferably 2.

Specifically, it is

-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-GGFGG-(NH-DX)-   —C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-GGFGGG-(NH-DX)

Examples of the drug-linker structure moiety in another form forconjugating the drug-linker structure moiety to the antibody via anamide bond can include the following formulas:

-   —C(═O)—(CH₂)n⁵-C(═O)-L²-GGFGG-(NH-DX)-   —C(═O)—(CH₂)n⁵-C(═O)-L²-GGFGGG-(NH-DX)

In the above formula, n⁵ is preferably 6, and L² is —NH—(CH₂—CH₂—O)n⁶-CH₂—CH₂—C(═O)— or a single bond and is preferably a single bond. n⁶is preferably 0, 2, or 4, and more preferably 0.

More specifically, it is

-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-GGFGG-(NH-DX)-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-GGFGGG-(NH-DX)    11. Specific Example when L¹ has Hydrophilic Structure

When linker L¹ is -(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—, thedrug-linker structure moiety is connected to the antibody via athioether bond, and is present in the form of-L¹-L²-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-DX) or -L¹-L²-L^(P)-(NH-DX).The combinations of each linker moiety constituting this drug-linkerstructure are as follows.

The linker L² in is NH—(CH₂—CH₂—O) n⁶-CH₂—CH₂—C(═O)— or a single bondand is preferably a single bond. n⁶ is preferably 0, 2, or 4, and morepreferably 0.

The amino acid sequence of linker L^(P) is not particularly limited, butexamples of the constituting amino acid include phenylalanine, tyrosine,leucine, glycine, alanine, valine, lysine, citrulline, serine, glutamicacid, and aspartic acid. Among them, preferred examples includephenylalanine, glycine, valine, lysine, citrulline, serine, glutamicacid, and aspartic acid. Depending on the type of the amino acid, drugrelease pattern can be controlled. The number of the amino acid can bebetween 3 to 8. Specific examples thereof are as listed above, and GGFGis particularly preferred.

The linker —NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- moiety preferably has a chainlength of 4 to 7 atoms. The moiety more preferably has a chain length of5 or 6 atoms in the linker. Specific examples of the—NH—(CH₂)n¹-L^(a)-L^(b)-moiety in the linker are as described above.

The —NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- moiety may be a single bond.

The linker -L^(c)- moiety is preferably —C(═O)—.

The drug-linker structure moiety in which linker L¹ is-(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)— is connected to theantibody via a thioether bond and has a structure represented by thefollowing formula:

-   -(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—NH—(CH₂—CH₂—O)    n⁶-CH₂—CH₂—C(═O)-GGFG-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)

In the above formula, n⁶ is 0. Preferably, n³ is 2 to 4, and the—NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- moiety is —NH—CH₂CH₂—C(═O)—,—NH—CH₂CH₂CH₂—C(═O)—, —NH—CH₂—O—CH₂—C(═O)—, or —NH—CH₂CH₂—O—CH₂—C(═O)—.Also, those which L^(P) is directly connected to the drug arepreferable.

More specifically, it is represented by the following formula:

-   -(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)    or the following formula:-   -(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-(NH-DX)

In the above formula, n³ is preferably 2, and it is preferablyrepresented by the following formula:

-   -(Succinimid-3-yl-N)—CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)    or the following formula:-   -(Succinimid-3-yl-N)—CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-(NH-DX)    12. Specific Example when L² has Hydrophilic Structure

When linker L² is —N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)—, thedrug-linker structure moiety is present in the form of-L¹-L²-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX) or-L¹-L²-L^(P)-(NH-DX). The combinations of each linker moietyconstituting this drug-linker structure moiety are as follows.

When the drug-linker structure moiety is connected to the antibody via athioether bond, linker L¹ is -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)— or—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—, and when the drug-linker structure moietyis connected to the antibody via an amide bond, it is selected from—C(═O)—(CH₂)n⁵-C(═O)—.

The amino acid sequence of linker L^(P) is not particularly limited, butexamples of the constituting amino acid can include phenylalanine,tyrosine, leucine, glycine, alanine, valine, lysine, citrulline, serine,glutamic acid, and aspartic acid. Among them, preferred examples caninclude phenylalanine, glycine, valine, lysine, citrulline, serine,glutamic acid, and aspartic acid. Depending on the type of the aminoacid, drug release pattern can be controlled. The number of the aminoacid can be between 3 to 8. Specific examples thereof are as listedabove. GGFG is particularly preferred.

The linker —NH—(CH₂)n¹-L^(a)-L^(b)-L^(c) moiety preferably has a chainlength of 4 to 7 atoms. The moiety more preferably has a chain length of5 or 6 atoms in the linker. Specific examples of the—NH—(CH₂)n¹-L^(a)-L^(b)-moiety in the linker are as described above.

The —NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- moiety may be a single bond.

The linker -L^(c)- moiety is preferably —C(═O)—.

The drug-linker structure moiety in which linker L² is —N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)— is preferably represented by the followingformula:

-   -L¹-N[—(CH₂CH₂—O)    n⁷-CH₂CH₂—OH]-CH₂—C(═O)-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)

The drug-linker structure moiety for conjugating the drug-linkerstructure moiety to the antibody via a thioether bond is represented bythe following formula:

-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)—N[—(CH₂CH₂—O)    n⁷-CH₂CH₂—OH]-CH₂—C(═O)-GGFG-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)

In the above formula, preferably, n² is 2 or 5, n⁷ is 3 or 4, and the—NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- moiety is —NH—CH₂CH₂—C(═O)—,—NH—CH₂CH₂CH₂—C(═O)—, —NH—CH₂—O—CH₂—C(═O)—, or —NH—CH₂CH₂—O—CH₂—C(═O)—.Also, those which L^(P) is directly connected to the drug arepreferable.

More specifically, it is represented by the following formula:

-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)—N[—(CH₂CH₂—O)    n⁷-CH₂CH₂—OH]-CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)—N[—(CH₂CH₂—O)    n⁷-CH₂CH₂—OH]-CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)—N[—(CH₂CH₂—O)    n⁷-CH₂CH₂—OH]-CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)—N[—(CH₂CH₂—O)    n⁷-CH₂CH₂—OH]-CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)    or the following formula:-   -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)—N[—(CH₂CH₂—O)    n⁷-CH₂CH₂—OH]-CH₂—C(═O)-GGFG-(NH-DX)

Further preferably, n² is 5, n⁷ is 3 or 4, and more preferably 3, and itis preferably represented by the following formulas:

-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)—(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)    or the following formula:-   -(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-(NH-DX)

Examples of the drug-linker structure moiety as another form forconjugating the drug-linker structure moiety to the antibody via athioether bond can include the following formula:

-   —CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—N[—(CH₂CH₂—O)    n⁷-CH₂CH₂—OH]-CH₂—C(═O)-GGFG-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)

In the above formula, preferably, n⁴ is 2 or 5, n⁷ is 3 or 4, and the—NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- moiety is —NH—CH₂CH₂—C(═O)—,—NH—CH₂CH₂CH₂—C(═O)—, —NH—CH₂—C—CH₂—C(═O)—, or —NH—CH₂CH₂—O—CH₂—C(═O)—.Also, those which L^(P) is directly connected to the drug arepreferable.

Specifically, it is represented by the following formula:

-   —CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)    or the following formula:-   —CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)-GGFG-(NH-DX)

In the above formula, preferably, n⁴ is 2, n⁷ is 3 or 4, and morepreferably 3, and it is represented by the following formulas:

-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)—(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX)    or the following formula:-   —CH₂—C(═O)—NH—CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-(NH-DX)

Alternatively, the drug-linker structure moiety for conjugating thedrug-linker structure moiety to the antibody via an amide bond isrepresented by the following formula:

-   —C(═O)—(CH₂)n⁵-C(═O)—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)-GGFG-NH—(CH₂)    n¹-L^(a)-L^(b)-L^(c)-(NH-DX)

In the above formula, preferably, n⁵ is an integer of 1 to 8 and is morepreferably 2 to 6, n⁷ is 3 or 4, and the —NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-moiety is —NH—CH₂CH₂—C(═O)—, —NH—CH₂CH₂CH₂—C(═O)—, —NH—CH₂—O—CH₂—C(═O)—,or —NH—CH₂CH₂—O—CH₂—C(═O)—. Also, those which L^(P) is directlyconnected to the drug are preferable.

More specifically, it is represented by the following formula:

-   —C(═O)—(CH₂)n⁵-C(═O)—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   —C(═O)—(CH₂)n⁵-C(═O)—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   —C(═O)—(CH₂)n⁵-C(═O)—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   —C(═O)—(CH₂)n⁵-C(═O)—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)    or the following formula:-   —C(═O)—(CH₂)n⁵-C(═O)—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)-GGFG-(NH-DX)

Further preferably, n⁵ is 6, n⁷ is 3 or 4, and more preferably 3, and itis represented by the following formulas:

-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)    or the following formula:-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-(NH-DX)

Further preferably, it is represented by the following formula:

-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX)    or the following formula:-   —C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-(NH-DX)

[Production Method]

Next, explanations are given for the representative method for producingthe antibody-drug conjugate of the present invention or a productionintermediate thereof. Meanwhile, the compounds are hereinbelow describedwith the number shown in each reaction formula. Specifically, they arereferred to as a “compound of the formula (1)”, a “compound (1)”, or thelike. The compounds with numbers other than those are also describedsimilarly.

1. Production Method 1

The antibody-drug conjugate represented by the formula (1) in which theantibody is connected to the linker structure via thioether can beproduced by the following method, for example.

In the formula, AB represents an antibody with a sulfhydryl group, andL^(1′) represents an L¹ linker structure in which the linker terminalhas a maleimidyl group (formula shown below) (in the formula, thenitrogen atom is the connecting position)

or the terminal has a halogen, and represents a group in which the-(Succinimid-3-yl-N)— moiety in -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)—among L¹ is a maleimidyl group or a halogen-CH₂C(═O)NH—(CH₂)n³-C(═O)—group in which terminal methylene in —CH₂C(═O) NH—(CH₂)n⁴-C(═O)— amongL¹ is halogenated to form haloacetamide. Further, the —(NH-DX)represents a structure represented by the following formula:

and it represents a group that is produced by removing one hydrogen atomof the amino group at position 1 of the antitumor drug. Meanwhile, thecompound of the formula (1) in the above reaction formula is describedas a structure in which one structure moiety from drug to the linkerterminal is connected to one antibody. However, it is only thedescription given for the sake of convenience, and there are actuallymany cases in which a plurality of the structure moieties are conectedto one antibody molecule. The same also applies to the explanation ofthe production method described below.

Specifically, the antibody-drug conjugate (1) can be produced byreacting the compound (2), which is obtainable by the method describedbelow, with the antibody (3a) having a sulfhydryl group.

The antibody (3a) having a sulfhydryl group can be obtained by a methodwell known in the art (Hermanson, G. T, Bioconjugate Techniques, pp.56-136, pp. 456-493, Academic Press (1996)). Examples include: Traut'sreagent is reacted with the amino group of the antibody; N-succinimidylS-acetylthioalkanoates are reacted with the amino group of the antibodyfollowed by reaction with hydroxylamine; after reacting withN-succinimidyl 3-(pyridyldithio)propionate, it is reacted with areducing agent; the antibody is reacted with a reducing agent such asdithiothreitol, 2-mercaptoethanol, and tris(2-carboxyethyl)phosphinehydrochloride (TCEP) to reduce the disulfide bond at a hinge part in theantibody, but it is not limited thereto.

Specifically, the antibody-drug conjugate (1) can be produced by addingdimethyl sulfoxide solution of the compound (2) into aphosphate-buffered sodium chloride aqueous soluiton (pH 7.2) containingthe antibody (3a) having a sulfhydryl group. Then, as is ordinary usedin the reaction for the production of antibody-drug bond formation,unreacted compound (2) was deactivated by the addition ofN-acetyl-L-cysteine (NAC). The produced antibody-drug conjugate (1) canbe subjected to the follwing procedures such as, concentration, bufferexchange, conducting purification, measurement of antibody concentrationand average number of conjugated drug molecules per antibody molecule,and calculation of aggregate content, identification of theantibody-drug conjugate (1).

Common procedure A: Concentration of aqueous solution of antibody orantibody-drug conjugate

To a Amicon Ultra (50,000 MWCO, Millipore Corporation) container, asolution of antibody or antibody-drug conjugate was added and thesolution of the antibody or antibody-drug conjugate was concentrated bycentrifugation (centrifuge for 5 to 20 minutes at 2000 G to 3800 G)using a centrifuge (Allegra X-15R, Beckman Coulter, Inc.).

Common procedure B: Measurement of antibody concentration

Using a UV detector (Nanodrop 1000, Thermo Fisher Scientific Inc),measurement of the antibody concentration was performed according to themethod defined by the manufacturer. At that time, 280 nm absorptioncoefficient different for each antibody was used (1.3 to 1.8/mg/mL).

Common procedure C-1: NAP-25 column (Cat. No. 17-0852-02, GE HealthcareJapan Corporation) using Sephadex G-25 carrier was equilibrated withphosphate buffer (10 mM, pH 6.0) (it is referred to as PBS6.0/EDTA inthe specification) containing sodium chloride (137 mM) and ethylenediamine tetraacetic acid (EDTA, 5 mM) according to the method defined bythe manufacturer's instruction manual. Aqueous solution of the antibodywas applied in an amount of 2.5 mL to single NAP-25 column, and then thefraction (3.5 mL) eluted with 3.5 mL of PBS6.0/EDTA was collected. Theresulting fraction was concentrated by the Common procedure A. Aftermeasuring the concentration of the antibody using the Common procedureB, the antibody concentration was adjusted to 10 mg/mL usingPBS6.0/EDTA.

Common procedure C-2: Buffer Exchange for antibody

NAP-25 column (Cat. No. 17-0852-02, GE Healthcare Japan Corporation)using Sephadex G-25 carrier was equilibrated with phosphate buffer (50mM, pH 6.5) (it is referred to as PBS6.5/EDTA in the specification)containing sodium chloride (50 mM) and EDTA (2 mM) according to themethod defined by the manufacturer. Aqueous solution of the antibody wasapplied in an amount of 2.5 mL to single NAP-25 column, and then thefraction (3.5 mL) eluted with 3.5 mL of PBS6.5/EDTA was collected. Theresulting fraction was concentrated by the Common procedure A. Aftermeasuring the concentration of the antibody using the Common procedureB, the antibody concentration was adjusted to 20 mg/mL usingPBS6.5/EDTA.

Common procedure D-1: Purification of antibody-drug conjugate

NAP-25 column was equilibrated with any buffer selected fromcommercially available phosphate buffer (PBS7.4, Cat. No. 10010-023,Invitrogen), sodium phosphate buffer (10 mM, pH 6.0; it is referred toas PBS6.0) containing sodium chloride (137 mM), and acetate buffercontaining sorbitol (5%) (10 mM, pH 5.5; it is referred to as ABS in thespecification). Aqueous solution of the antibody-drug conjugate reactionwas applied in an amount of about 1.5 mL to the NAP-25 column, and theneluted with the buffer in an amount defined by the manufacturer tocollect the antibody fraction. The collected fraction was again appliedto the NAP-25 column and, by repeating 2 to 3 times in total the gelfiltration purification process for eluting with buffer, theantibody-drug conjugate excluding non-conjugated drug linker and alow-molecular-weight compound (tris(2-carboxyethyl)phosphinehydrochloride (TCEP), N-acetyl-L-cysteine (NAC), and dimethyl sulfoxide)was obtained.

Common procedure D-2: Purification of succinimidyl4-(N-maleimidylmethyl)-cyclohexane-1-carboxylate (SMCC)-derivatizedantibody

NAP-25 column was equilibrated with PBS6.5/EDTA. To the NAP-25 column,reaction solution (about 0.5 mL) containing the succinimidyl4-(N-maleimidylmethyl)-cyclohexane-1-carboxylate (herein, referred to asSMCC)-derivatized antibody was applied, and then eluted with the bufferin an amount defined by the manufacturer to collect the antibodyfraction for purification.

Common procedure E: Measurement of antibody concentration inantibody-drug conjugate and average number of conjugated drug moleculesper antibody molecule.

The conjugated drug concentration in the antibody-drug conjugate can becalculated by measuring UV absorbance of an aqueous solution of theantibody-drug conjugate at two wavelengths of 280 nm and 370 nm,followed by performing the calculation shown below.

Because the total absorbance at any wavelength is equal to the sum ofthe absorbance of every light-absorbing chemical species that arepresent in a system [additivity of absorbance], when the molarabsorption coefficients of the antibody and the drug remain the samebefore and after conjugation between the antibody and the drug, theantibody concentration and the drug concentration in the antibody-drugconjugate are expressed with the following equations.

A ₂₈₀ =A _(D,280) A _(A,280)=ε_(D,280) C _(D)+ε_(A,280) C _(A)  Equation(1)

A ₃₇₀ =A _(D,370) A _(A,370)=ε_(D,370) C _(D)+ε_(A,370) C _(A)  Equation(2)

In the above, A₂₈₀ represents the absorbance of an aqueous solution ofthe antibody-drug conjugate at 280 nm; A₃₇₀ represents the absorbance ofan aqueous solution of the antibody-drug conjugate at 370 nm; A_(A,280)represents the absorbance of an antibody at 280 nm; A_(A,370) representsthe absorbance of an antibody at 370 nm; A_(D,280) represents theabsorbance of a conjugate precursor at 280 nm; A_(D,370) represents theabsorbance of a conjugate precursor at 370 nm; ε_(A,280) represents themolar absorption coefficient of an antibody at 280 nm; ε_(A,370)represents the molar absorption coefficient of an antibody at 370 nm;ε_(D,280) represents the molar absorption coefficient of a conjugateprecursor at 280 nm; ε_(D,370) represents the molar absorptioncoefficient of a conjugate precursor at 370 nm; C_(A) represents theantibody concentration in an antibody-drug conjugate; and C_(D)represent the drug concentration in an antibody-drug conjugate.

ε_(A,280), ε_(A,370), ε_(D,280), and ε_(D,370) in the above are knownfrom the previous measurements By measuring A₂₈₀ and A₃₇₀ of an aqueoussolution of the antibody-drug conjugate and solving the simultaneousequations (1) and (2) using the values, C_(A) and C_(D) can be obtained.Further, by diving C_(D) by C_(A), the average drug conjugated numberper antibody can be obtained.

The compound represented by the formula (2) in Production method 1 isany compound represented by the following formula:

In the formula, n¹, n², n³, n⁴, n⁷, L², L^(P), L^(a), L^(b), and L^(c)are as already defined, and L^(P) or L^(c) is a connecting position tothe drug.

In an intermediate useful in producing such an antibody-drug conjugateof the present invention, preferably,

n² is an integer of 2 to 5,when L¹ in the linker is not-(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—, L² is —N[(—CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)—, and n⁷ is 3 or 4, or a single bond, what ispreferable for L^(P),when this is a peptide residue having a hydrophilic amino acid at the Nterminal, is DGGF, KGGF, EGGF, DGGFG, KGGFG, or EGGFG, orwhen this is a peptide linker having a glycine oligopeptide at the Cterminal, is GGFGG or GGFGGG and the —NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-moiety is a partial structure of —NH—CH₂CH₂—C(═O)—,—NH—CH₂CH₂CH₂—C(═O)—, —NH—CH₂—O—CH₂—C(═O)—, or —NH—CH₂CH₂—O—CH₂—C(═O)—.

And, those which L^(P) is directly connected to the drug are preferable,in case the peptide linker has a glycine oligopeptide at its C terminal,this C terminal is directly connected to the drug.

Specific examples of these compounds can include the followings [herein,(maleimid-N-yl) represents a maleimidyl group(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl group)].

When linker L^(P) is a peptide linker which has a hydrophilic amino acidat the N terminal, a compound having a structure represented by thefollowing formula can be preferably used as a production intermediate:

-   (maleimid-N-yl)-(CH₂)n²-C(═O)-DGGF-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)—KGGF-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)-DGGFG-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)-KGGFG-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)

In the above formula, preferably, n² is 2 to 5, and the—NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- moiety is —NH—CH₂CH₂—C(═O)—,—NH—CH₂CH₂CH₂—C(═O)—, —NH—CH₂—O—CH₂—C(═O)—, or —NH—CH₂CH₂—O—CH₂—C(═O)—.Also, those which L^(P) is directly connected to the drug arepreferable.

More specifically, it is represented by the following formula:

-   (maleimid-N-yl)-(CH₂)n²-C(═O)-DGGF—NH—CH₂CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)-DGGF—NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)-DGGF—NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)-KGGF—NH—CH₂CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)-KGGF—NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)-KGGF—NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)—KGGF—NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)-DGGFG-NH—CH₂CH₂—C(═O)—(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)—KGGFG-NH—CH₂CH₂—C(═O)—(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)-KGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)—KGGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)—KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX)    or the following formulas:-   (maleimid-N-yl)-(CH₂)n²-C(═O)-DGGF-(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)-KGGF-(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)-DGGFG-(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)-KGGFG-(NH-DX)

In the above formula, preferably, n² is 2 or 5.

Among them, further preferably, n² is 5, and it is represented by thefollowing formulas:

-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—C(═O)—(NH-DX)-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGF—NH—CH₂CH₂—C(═O)—(NH-DX)-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)    or the following formulas:-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF-(NH-DX)-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGF-(NH-DX)-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-(NH-DX)-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-KGGFG-(NH-DX)

When linker L^(P) is a peptide linker which has a glycine oligopeptideat the C terminal, a compound having a structure represented by thefollowing formula can be preferably used as a production intermediate:

-   (maleimid-N-yl)-(CH₂)n²-C(═O)-GGFGG-(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)-GGFGGG-(NH-DX) In the above formula,    n² is preferably 2 to 5.

Among them, further preferably, n² is 5, and it is represented by thefollowing formula:

-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-GGFGG-(NH-DX)-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)-GGFGGG-(NH-DX)

When linker L¹ in -(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—, acompound having a structure represented by the following formula can bepreferably used as a production intermediate:

-   (maleimid-N-yl)-CH[—(CH₂)n³-COOH]—C(═O)—NH—(CH₂—CH₂—O)    n⁶-CH₂—CH₂—C(═O)-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)

In the above formula, n⁶ is 0. Preferably, n³ is 2 to 4, and the—NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- moiety is —NH—CH₂CH₂—C(═O)—,—NH—CH₂CH₂CH₂—C(═O)—, —NH—CH₂—O—CH₂—C(═O)—, or —NH—CH₂CH₂—O—CH₂—C(═O)—.Also, those which L^(P) is directly connected to the drug arepreferable. L^(P) is preferably GGFG.

More specifically, it is represented by the following formula:

-   (maleimid-N-yl)-CH[—(CH₂)n³-COOH]—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-CH[—(CH₂)n³-COOH]—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-CH[—(CH₂)n³-COOH]—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-CH[—(CH₂)n³-COOH]—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)    or the following formula:-   (maleimid-N-yl)-CH[—(CH₂)n³-COOH]—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-(NH-DX)

In the above formula, n³ is preferably 2, and it is preferablyrepresented by the following formula:

-   (maleimid-N-yl)-CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)    or the following formula:-   (maleimid-N-yl)-CH(CH₂CH₂—COOH)—C(═O)—NH—CH₂CH₂—C(═O)-GGFG-(NH-DX)

When linker L² is —N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)—, a compoundhaving a structure represented by the following formula can bepreferably used as production intermediate:

-   (maleimid-N-yl)-(CH₂)n²-C(═O)—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)

In the above formula, preferably, n² is 2 to 5, n⁷ is 3 or 4, and the—NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- moiety is —NH—CH₂CH₂—C(═O)—,—NH—CH₂CH₂CH₂—C(═O)—, —NH—CH₂—O—CH₂—C(═O)—, or —NH—CH₂CH₂—O—CH₂—C(═O)—.Also those which L^(P) is directly connected to the drug are preferable.L^(P) is preferably GGFG.

More specifically, it is represented by the following formulas:

-   (maleimid-N-yl)-(CH₂)n²-C(═O)—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)—N[—(CH₂CH₂—O)    n⁷-CH₂CH₂—OH]-CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-(CH₂)n²-C(═O)—N[—(CH₂CH₂—O)    n⁷-CH₂CH₂—OH]-CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)    or the following formula:-   (maleimid-N-yl)-(CH₂)n²-C(═O)—N[—(CH₂CH₂—O)    n⁷-CH₂CH₂—OH]-CH₂—C(═O)-GGFG-(NH-DX)

Further preferably, n² is 5, n⁷ is 3 or 4, and more preferably 3, and itis represented by the following formulas;

-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX)    or the following formula:-   (maleimid-N-yl)-CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-(NH-DX)

In case when a halogenoacetyl group is present and peptide linker has ahydrophilic amino acid at the N terminal, a compound having a structurerepresented by the following formula can be preferably used as aproduction intermediate:

-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-DGGF-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-KGGF-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-EGGF-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-DGGFG-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-KGGFG-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-EGGFG-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)

In the above formula, preferably, n⁴ is 2 to 5, and the—NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- moiety is —NH—CH₂CH₂—C(═O)—,—NH—CH₂CH₂CH₂—C(═O)—, —NH—CH₂—O—CH₂—C(═O)—, or —NH—CH₂CH₂—O—CH₂—C(═O)—.Also, those which L^(P) is directly connected to the drug arepreferable. X is preferably bromine or iodine.

More specifically, it is more preferably represented by the followingformulas:

-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-DGGF-NH—CH₂CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-DGGF-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-DGGF-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-DGGF-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—KGGF-NH—CH₂CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—KGGF-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—KGGF-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—KGGF-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-DGGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—KGGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-KGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—KGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX)    or the following formulas:-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-DGGF-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-KGGF-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-DGGFG-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-KGGFG-(NH-DX)

Further preferably, n⁴ is 2, and it is represented by the followingformulas:

-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGF-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX)-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-KGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX)    or the following formulas:-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF-(NH-DX)-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-KGGF-(NH-DX)-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-(NH-DX)-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-KGGFG-(NH-DX)

In the above formula, X represents a bromine atom or an iodine atom. Allof these bromine and iodine compounds can be preferably used asproduction intermediates.

In case when halogenoacetyl group is present and the peptide linker hasa glycine oligopeptide at the C terminal, a compound having a structurerepresented by the following formula can be preferably used as aproduction intermediate:

-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-GGFGG-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)-GGFGGG-(NH-DX)

Preferably, n⁴ is 2 or 5, and more preferably 2, and it is representedby the following formula:

-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-GGGFG-(NH-DX)-   X—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-GGFGGG-(NH-DX)

In the above formula, X represents a bromine atom or an iodine atom. Allof these bromine and iodine compounds can be preferably used asproduction intermediates.

When linker L² is —N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)—, a compoundhaving a structure represented by the following formula can bepreferably used as a production intermediate:

-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)

In the above formula, preferably, n⁴ is 2 to 5, n⁷ is 3 or 4, and the—NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- moiety is —NH—CH₂CH₂—C(═O)—,—NH—CH₂CH₂CH₂—C(═O)—, —NH—CH₂—O—CH₂—C(═O)—, or —NH—CH₂CH₂—O—CH₂—C(═O)—.Also, those which L^(P) is directly connected to the drug arepreferable. L^(P) is preferably GGFG.

Specifically, it is represented by the following formula:

-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—N[—(CH₂CH₂—O)    n⁷-CH₂CH₂—OH]—CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—N[—(CH₂CH₂—O)    n⁷-CH₂CH₂—OH]—CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—N[—(CH₂CH₂—O)    n⁷-CH₂CH₂—OH]—CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—N[—(CH₂CH₂—O)    n⁷-CH₂CH₂—OH]—CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)    or the following formula:-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—N[—(CH₂CH₂—O)    n⁷-CH₂CH₂—OH]—CH₂—C(═O)-GGFG-(NH-DX)

Further preferably, n⁴ is 2, n⁷ is 3 or 4, and more preferably 3, and itis represented by the following formulas:

-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)    or the following formula:-   X—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-(NH-DX)

In order to secure the amount of the conjugate, a plurality ofconjugates obtained under similar production conditions to have anequivalent number of drugs (e.g., about ±1) can be mixed to prepare newlots. In this case, the average number of drugs falls between theaverage numbers of drugs in the conjugates before the mixing.

2. Production Method 2

The antibody-drug conjugate represented by the formula (1) or apharmacologically acceptable salt thereof, in which the bond to theantibody is amide group and has thioether bond within the linker,specifically, a structure in which -L¹-L²- is—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-dimiccuS)-S—(CH₂)n⁸-C(═O)—, can be alsoproduced by the following method.

[In the formula, AB-L¹′ represents that the antibody is connected tolinker L¹, and the terminal of L¹ is converted to a N-maleimidyl group.This group specifically has a structure in which —(N-ly-3-dimiccuS)-inAB—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-dimiccuS)- is converted to amaleimidyl group. L²′ represents a HS—(CH₂)n⁸-C(═O)— group in which theterminal is a mercapto group, and AB represents the antibody.]

Specifically, the antibody-drug conjugate (1) can be produced byreacting the compound (2a), which is obtainable by the method describedbelow, with the antibody (3b) to which the linker having a maleimidylgroup is connected.

The antibody (3b) having a maleimidyl group can be also obtained by amethod well known in the art (Hermanson, G. T, Bioconjugate Techniques,pp. 56-136, pp. 456-493, Academic Press (1996)). Example includes amethod in which a bifunctional linker such assuccinimidyl-4-(N-maleimidomethyl)cyclohexane-1-carboxylate (SMCC),which is capable of connecting to an amino group or a hydroxyl group, isallowed to act on the amino group of the antibody so as to introduce amaleimidyl group, but it is not limited thereto.

For example, a compound having an amino group-reactive moiety and athiol group-reactive moiety are connected via a linker can be preferablyused. Here, the amino group-reactive moiety can be active ester, imideester, or the like, and the thiol-reactive moiety can be maleimidyl,halogenated acetyl, halogenated alkyl, dithiopyridyl, or the like.

As a method for constructing the linker via an amide bond with the aminogroup or hydroxy group, particularly, the amino group, of an amino acidconstituting antibody, the compound to be first reacted with theantibody can be a compound represented by the following formula:

-   Q¹-L^(1a)-Q².

In the formula, Q¹ represents (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—,(3-Sulfo-pyrrolidine-2,5-dione-N-yl)-O—C(═O)—, R^(Q)—O—C(═N)—, orO═C═N—,

L^(1a)-represents -cyc.Hex(1,4)-CH₂—, an alkylene group having 1 to 10carbon atoms, a phenylene group, —(CH₂)n⁴-C(═O)—,—(CH₂)n^(4a)-NH—C(═O)—(CH₂)n^(4b)-, or—(CH₂)n^(4a)-NH—C(═O)-cyc.Hex(1,4)-CH₂—,Q² represents (maleimid-N-yl), a halogen atom, or —S—S-(2-Pyridyl),R^(Q) represents an alkyl group having 1 to 6 carbon atoms,n⁴ represents an integer of 1 to 8, n^(4a) represents an integer of 0 to6, and n^(4b) represents an integer of 1 to 6.

In the above, R^(Q) is an alkyl group having 1 to 6 carbon atoms, andmore preferably a methyl group or an ethyl group.

The alkylene group of L^(1a) may be those having 1 to 10 carbon atoms.The phenylene group may be any of ortho, meta, and para and is morepreferably a para- or meta-phenylene group.

Preferred examples of L^(1a) can include -cyc.Hex(1,4)-CH₂—,—(CH₂)₅—NH—C(═O)-cyc.Hex(1,4)-CH₂—, —(CH₂)₂—NH—C(═O)—CH₂—,—(CH₂)₅—NH—C(═O)—(CH₂)₂, CH₂, —(CH₂)₂, —(CH₂)₃, —(CH₂)₅—, —(CH₂)₁₀—,-(para-Ph)-, -(meta-Ph)-, -(para-Ph)-CH(—CH₃)—, —(CH₂)₃-(meta-Ph)-, and-(meta-Ph)—NH—C(═O)—CH₂—.

Q¹ is preferably (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)— and Q² ispreferably (maleimid-N-yl), or —S—S-(2-Pyridyl) can be used when adisulfide bond is to be formed.

In the above, (Pyrrolidine-2,5-dione-N-yl)- is a group represented bythe following formula:

wherein the nitrogen atom is the connecting position,(3-Sulfo-pyrrolidine-2,5-dione-N-yl)- is a group represented by thefollowing formula:

wherein the nitrogen atom is the connecting position, and this sulfonicacid is capable of forming a lithium salt, sodium salt, or potassiumsalt, and preferably sodium salt,cyc.Hex(1,4) represents a 1,4-cyclohexylene group, (maleimid-N-yl) is agroup represented by the following formula:

wherein the nitrogen atom is the connecting position, (2-Pyridyl)represents a 2-pyridyl group, (para-Ph) represents a para-phenylenegroup, and (meta-Ph) represents a meta-phenylene group.

As for such a compound other than the compounds described above,sulfosuccinimidyl-4-(N-maleimidylmethyl)cyclohexane-1-carboxylate(sulfo-SMCC),N-succinimidyl-4-(N-maleimidylmethyl)-cyclohexane-1-carboxy-(6-amidocaproate)(LC-SMCC), κ-maleimidyl undecanoic acid N-succinimidyl ester (KMUA),γ-maleimidyl butyric acid N-succinimidyl ester (GMBS), ε-maleimidylcaproic acid N-hydroxysuccinimide ester (EMCS),m-maleimidylbenzoyl-N-hydroxysuccinimide ester (MBS),N-(α-maleimidylacetoxy)-succinimide ester [AMAS],succinimidyl-6-(β-maleimidylpropionamide)hexanoate (SMPH),N-succinimidyl 4-(p-maleimidylphenyl)-butyrate (SMPB),N-(p-maleimidylphenyl)isocyanate (PMPI),N-succinimidyl-4-(iodoacetyl)-aminobenzoate (SIAB), N-succinimidyliodoacetate (SIA), N-succinimidyl bromoacetate (SBA), N-succinimidyl3-(bromoacetamide)propionate (SBAP),N-succinimidyl-3-(2-pyridodithio)propionate (SPDP), andsuccinimidyloxycarbonyl-α-methyl-α-(2-pyridyldithio)toluene (SMPT) canbe used.

Specifically, for example, by reacting 2 to 6 equivalents of SMCC withthe antibody (3) in a phosphate buffer of pH 6 to 7 at room temperaturefor 1 to 6 hours, the active ester of SMCC can react with the antibodyto yield the antibody (3b) having a maleimidyl group. The obtainedantibody (3b) can be purified by Common procedure D-2 described below,and used for the next reaction with the compound (2).

The amino group and hydroxyl group of the antibody refer to, forexample, a N-terminal amino group carried by the antibody and/or anamino group carried by a lysine residue and a hydroxy group carried by aserine residue, respectively, but they are not limited thereto.

For the produced antibody-drug conjugate (1), concentration, bufferexchange, purification, and identification of the antibody-drugconjugate (1) by the measurement of antibody concentration and anaverage number of conjugated drug molecules per antibody molecule andcalculation of aggregate content can be performed in the same manner asProduction method 1.

The compound represented by the formula (3b) in Production method 2 hasthe following structure (see the following formula; in the structurethereof, “antibody-NH-” originates from an antibody).

A compound which is an intermediate for producing the antibody-drugconjugate of the present invention and has the above structure is asdescribed below (in the formula, n is an integer of 1 to 10, preferably2 to 8, and more preferably 3 to 7).

Further, examples of the compound of the present invention in which theterminal is a mercapto group can include the followings.

When the peptide linker has a hydrophilic amino acid at the N terminal,a compound having a structure represented by the following formula canbe preferably used as a production intermediate:

-   HS—(CH₂)n⁸-C(═O)-DGGF-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   HS—(CH₂)n⁸-C(═O)—KGGF-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   HS—(CH₂)n⁸-C(═O)-DGGFG-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)-   HS—(CH₂)n⁸-C(═O)—KGGFG-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-(NH-DX)

In the above formula, preferably, n⁸ is 2 to 5, and the—NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- moiety is —NH—CH₂CH₂—C(═O)—,—NH—CH₂CH₂CH₂—C(═O)—, —NH—CH₂—O—CH₂—C(═O)—, or —NH—CH₂CH₂—O—CH₂—C(═O)—.Also, those which L^(P) is directly connected to the drug arepreferable.

More specifically, n⁸ is preferably 2, and it is represented by thefollowing formula:

-   HS—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—C(═O)-(NH-DX)-   HS—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   HS—CH₂CH₂—C(═O)-DGGF—NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   HS—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   HS—CH₂CH₂—C(═O)-KGGF—NH—CH₂CH₂—C(═O)-(NH-DX)-   HS—CH₂CH₂—C(═O)-KGGF—NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   HS—CH₂CH₂—C(═O)-KGGF—NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   HS—CH₂CH₂—C(═O)-KGGF—NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   HS—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   HS—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   HS—CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   HS—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)-   HS—CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂—C(═O)-(NH-DX)-   HS—CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂CH₂—C(═O)-(NH-DX)-   HS—CH₂CH₂—C(═O)-KGGFG-NH—CH₂—O—CH₂—C(═O)-(NH-DX)-   HS—CH₂CH₂—C(═O)-KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX)    or the following formulas:-   HS—CH₂CH₂—C(═O)-DGGF-(NH-DX)-   HS—CH₂CH₂—C(═O)-KGGF-(NH-DX)-   HS—CH₂CH₂—C(═O)-DGGFG-(NH-DX)-   HS—CH₂CH₂—C(═O)-KGGFG-(NH-DX)

When the peptide residue of the linker has a glycine oligopeptide at theC terminal, a compound having a structure represented by the followingformula can be preferably used as a production intermediate:

-   HS—(CH₂)n⁸-C(═O)-GGFGG-(NH-DX)-   HS—(CH₂)n⁸-C(═O)-GGFGGG-(NH-DX)

In the above formula, n⁸ is preferably 2 or 5.

More preferably, n⁸ is 2, and it is represented by the followingformula:

-   HS—CH₂CH₂—C(═O)-GGFGG-(NH-DX)-   HS—CH₂CH₂—C(═O)-GGFGGG-(NH-DX)

3. Production Method 3

The antibody-drug conjugate represented by the formula (1) or apharmacologically acceptable salt thereof in which the antibody isconjugated to the drug linker moiety via an amide bond can be producedby a method described below. For example, L¹′ in which L¹ is—C(═O)—(CH₂)n⁵-C(═O)—, and this is converted to active ester, forexample, (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—(CH₂)n⁵-C(═O)—, can bepreferably used. Further, when L² is a single bond, the antibody-drugconjugate (1) can be produced by the following method, for example.

Specifically, the antibody-drug conjugate (1) can be produced byreacting the compound (2b), which is obtainable by the method describedbelow, with the antibody (3).

The compound (2b) has a property capable of connecting to the aminogroup or hydroxyl group of the antibody. The amino group and hydroxylgroup of the antibody refer to, as described in Production method 2, forexample, a N-terminal amino group carried by the antibody and/or anamino group carried by a lysine residue and a hydroxy group carried by aserine residue, respectively, but they are not limited thereto.

The compound (2b) is an active ester composed of a N-hydroxysuccinimidylester group, and alternatively, other active esters, for example, asulfosuccinimidyl ester group, N-hydroxyphthalimidyl ester,N-hydroxysulfophthalimidyl ester, ortho-nitrophenyl ester,para-nitrophenyl ester, 2,4-dinitrophenyl ester,3-sulfonyl-4-nitrophenyl ester, 3-carboxy-4-nitrophenyl ester, andpentafluorophenyl ester, may be used.

As the reaction between compound (2b) and antibody (3), using 2 to 20molar equivalents of the compound (2b) per the antibody (3) in thereaction of the compound (2b) with the antibody (3), the antibody-drugconjugate (1) in which 1 to 10 drug molecules are conjugated perantibody can be produced. Specifically, the solution containing thecompound (2b) dissolved therein can be added to a buffer solutioncontaining the antibody (3) for the reaction to produce theantibody-drug conjugate (1). Herein, examples of the buffer solutionwhich may be used include sodium acetate solution, sodium phosphate, andsodium borate. pH for the reaction can be 5 to 9, and more preferablythe reaction is performed near pH 7. Examples of the solvent fordissolving the compound (2b) include an organic solvent such as dimethylsulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMA), andN-methyl-2-pyridone (NMP). It is sufficient that the organic solventsolution containing the compound (2b) dissolved therein is added at 1 to20% v/v to a buffer solution containing the antibody (3) for thereaction. The reaction temperature is 0 to 37° C., more preferably 10 to25° C., and the reaction time is 0.5 to 20 hours.

For the produced antibody-drug conjugate (1), concentration, bufferexchange, purification, and identification of the antibody-drugconjugate (1) by the measurement of antibody concentration and anaverage number of conjugated drug molecules per antibody molecule can beperformed in the same manner as Production method 1.

In Production method 3,(Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—(CH₂)n⁴-C(═O)— has the followingstructure.

Examples of the compound having the above partial structure and havingthe peptide linker having a hydrophilic amino acid at the N terminal caninclude the followings.

-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF—NH—CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF—NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX).

Among them, the followings are more preferred.

-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF—NH—CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—C(═O)—(NH-DX).

Examples of the compound having the above partial structure and havingthe peptide linker having a hydrophilic amino acid at the N terminal,which is directly connected to the drug can include the followings.

-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-(NH-DX).

Examples of the compound having the above partial structure and havingthe peptide linker having a glycine oligopeptide at the C terminal,which is directly connected to the drug can include the followings.

-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-GGFGG-(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-GGFGGG-(NH-DX).

Examples of the compound having the above partial structure and havingthe hydrophilic structure in L¹ can include the followings.

-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH(CH₂CH₂—COOH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH(CH₂CH₂—COOH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH(CH₂CH₂—COOH)—CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH(CH₂CH₂—COOH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX).

Examples of the compound having the above partial structure, having thehydrophilic structure in L¹, and having the peptide linker directlyconnected to the drug can include the followings.

-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH(CH₂CH₂—COOH)—CH₂—C(═O)-GGFG-(NH-DX).

Examples of the compound having the above partial structure and havingthe hydrophilic structure in L² can include the followings.

-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-NH—CH₂CH₂—O—CH₂—C(═O)-(NH-DX).

Examples of the compound having the above partial structure, having thehydrophilic structure in L², and the peptide linker directly connectedto the drug can include the followings.

-   (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—N(—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—OH)—CH₂—C(═O)-GGFG-(NH-DX).

4. Production Method 4

Among the compound represented by the formula (2) or (2b) used as anintermediate in the previous production method and a pharmacologicallyacceptable salt thereof, those in which the linker has a structurerepresented by -L¹-L²-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-, and L^(P) hasa hydrophilic amino acid other than glycine at the N terminal, forexample, can be produced by the following method.

In the formula, L^(c) is a —C(═O)— group, L¹′ represents L¹ structure inwhich the terminal is a maleimidyl group or a haloacetyl group, or L¹ isconverted to (Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—(CH₂)n⁵-C(═O)—, L^(P)represents a structure of -L^(p1)-L^(p2) and P¹, P², P³, P⁴, P⁵, P⁶, andP⁷ each represent a protecting group.

Since L^(P) is formed by connecting L^(p1) and L^(p2), the N-terminalhydrophilic amino acid of L^(P) is derived from L^(p1), therefore,L^(p1) having a hydrophilic amino acid at the N terminal can be used. Aplurality of hydrophilic amino acids may be present therein. If L^(p2)having a hydrophilic amino acid is used, according to its position,L^(P) can be produced so as to contain a plurality of hydrophilic aminoacids at the N terminal of L^(P) or at the N terminal and otherpositions.

The compound (6) can be produced by derivatizing the carboxylic acidcompound (5) having the terminal amino group protected with P¹ intoactive ester, mixed acid anhydride, acid halide, or the like andreacting it with NH₂-DX [which represents exatecan; chemical name:(1S,9S)-1-amino-9-ethyl-5-fluoro-2,3-dihydro-9-hydroxy-4-methyl-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolidino[1,2-b]quinoline-10,13(9H,15H)-dione] (that is, thepharmaceutical compound described in claim 2 of Japanese PatentLaid-Open No. 6-87746) (4) or a pharmacologically acceptable saltthereof in the presence of a base.

For this reaction, reagents and conditions commonly used for amidationand peptide synthesis can be employed. There are various kinds of activeester, for example, it can be produced by reacting phenols such asp-nitrophenol, N-hydroxy benzotriazole, N-hydroxy succinimide, or thelike, with the carboxylic acid compound (5) using a condensation agentsuch as N,N′-dicyclohexylcarbodiimide or1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride. Further,the active ester can be also produced by a reaction of the carboxylicacid compound (5) with pentafluorophenyl trifluoroacetate or the like; areaction of the carboxylic acid compound (5) with 1-benzotriazolyloxytripyrrolidinophosphonium hexafluorophosphite; a reaction of thecarboxylic acid compound (5) with diethyl cyanophosphonate (Shioirimethod); a reaction of the carboxylic acid compound (5) withtriphenylphosphine and 2,2′-dipyridyl disulfide (Mukaiyama's method); areaction of the carboxylic acid compound (5) with a triazine derivativesuch as 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholiniumchloride (DMTMM); or the like. Further, the reaction can be alsoperformed by, e.g., an acid halide method by which the carboxylic acidcompound (5) is treated with acid halide such as thionyl chloride oroxalyl chloride in the presence of a base. By reacting the active ester,mixed acid anhydride, or acid halide of the carboxylic acid compound (5)obtained above with the compound (4) in the presence of a suitable basein an solvent which does not inhibit a reaction at −78° C. to 150° C.,the compound (6) can be produced.

Specific examples of the base used for each step described above includecarbonate of an alkali metal or an alkali earth metal, an alkali metalalkoxide, hydroxide or hydride of an alkali metal including sodiumcarbonate, potassium carbonate, sodium ethoxide, potassium butoxide,sodium hydroxide, potassium hydroxide, sodium hydride, and potassiumhydride, organometallic base represented by an alkyl lithium includingn-butyl lithium, dialkylamino lithium including lithiumdiisopropylamide; organometallic base of bissilylamine including lithiumbis(trimethylsilyl)amide; and organic base including pyridine,2,6-lutidine, collidine, 4-dimethylaminopyridine, triethylamine,N-methylmorpholine, diisopropylethylamine, anddiazabicyclo[5.4.0]undec-7-ene (DBU).

Examples of the solvent, which is used for the reaction of the presentinvention and does not inhibit the reaction, include a halogenatedhydrocarbon solvent such as dichloromethane, chloroform, and carbontetrachloride; an ether solvent such as tetrahydrofuran,1,2-dimethoxyethane, and dioxane; an aromatic solvent such as benzeneand toluene; and an amide solvent such as N,N-dimethylformamide,N,N-dimethylacetamide, and N-methylpyrrolidin-2-one. In addition tothem, a sulfoxide solvent such as dimethyl sulfoxide and sulfolane; analcohol solvent such as methanol and ethanol; and a ketone solvent suchas acetone and methyl ethyl ketone may be used depending on a case.

The hydroxy group, carboxy group, amino group, or the like of L^(a) andL^(b) in the compound (6) may be protected by a protecting group whichis commonly used in organic compound synthesis, as mentioned later.

Specifically, examples of the protecting group for a hydroxyl groupinclude an alkoxymethyl group such as methoxymethyl group; an arylmethylgroup such as benzyl group, 4-methoxybenzyl group, and triphenylmethylgroup; an alkanoyl group such as acetyl group; an aroyl group such asbenzoyl group; and a silyl group such as tert-butyl diphenylsilyl group.Carboxy group can be protected, e.g., as an ester with an alkyl groupsuch as methyl group, ethyl group, and tert-butyl group, an allyl group,or an arylmethyl group such as benzyl group. Amino group can beprotected with a protecting group for an amino group which is generallyused for peptide synthesis, for example, an alkyloxy carbonyl group suchas tert-butyloxy carbonyl group, methoxycarbonyl group, ethoxycarbonylgroup, and 2-(trimethylsilyl)ethoxycarbonyl group; an arylmethyl groupsuch as allyloxycarbonyl, 9-fluorenylmethyloxy carbonyl group, benzyloxycarbonyl group, paramethoxybenzyloxy carbonyl group, and para (orortho)nitroybenzyloxy carbonyl group; an alkanoyl group such as acetylgroup; an arylmethyl group such as benzyl group and triphenyl methylgroup; an aroyl group such as benzoyl group; and an aryl sulfonyl groupsuch as 2,4-dinitrobenzene sulfonyl group or orthonitrobenzene sulfonylgroup. Protection with and deprotection of the protecting group can beperformed according to a method commonly carried out in the art.

As for the protecting group P¹ for the terminal amino group of thecompound (6), a protecting group for an amino group which is generallyused for peptide synthesis, for example, tert-butyloxy carbonyl group,9-fluorenylmethyloxy carbonyl group, and benzyloxy carbonyl group, canbe used. Examples of the other protecting group for an amino groupinclude an alkanoyl group such as acetyl group; an alkoxycarbonyl groupsuch as methoxycarbonyl group and ethoxycarbonyl group; an arylmethoxycarbonyl group such as paramethoxybenzyloxy carbonyl group, and para (orortho)nitroybenzyloxy carbonyl group; an arylmethyl group such as benzylgroup and triphenyl methyl group; an aroyl group such as benzoyl group;and an aryl sulfonyl group such as 2,4-dinitrobenzene sulfonyl group andorthonitrobenzene sulfonyl group. The protecting group P¹ can beselected depending on, e.g., properties of a compound having an aminogroup to be protected.

By deprotecting the protecting group P¹ for the terminal amino group ofthe compound (6) obtained, the compound (7) can be produced. Reagentsand conditions can be selected depending on the protecting group.

By derivatizing the peptide or amino acid (8), which is protected by P²at its N terminal, into an active ester, mixed acid anhydride, or thelike and reacting it with the compound (7) obtained, the compound (9)can be produced. The reaction conditions, reagents, base, and solventused for forming a amide bond between the peptide or amino acid (8) andthe compound (7) are not limited as long as they do not inhibit areaction, and can be suitably selected from those described for thesynthesis of the compound (6). The protecting group P² for an aminogroup can be suitably selected from those described for the protectinggroup of the compound (6), and the selection can be made based on, e.g.,the properties of the compound. As it is generally used for peptidesynthesis, by repeating sequentially the reaction and deprotection ofthe amino acid or peptide constituting the peptide or amino acid (8) forelongation, the compound (9) can be also produced.

By deprotecting P² as the protecting group for the amino group of thecompound (9) obtained, the compound (10) can be produced. Reagents andconditions can be selected depending on the protecting group.

By derivatizing the amino acid or peptide (11) having the N terminalprotected with P³ and a side chain carboxy group, hydroxy group, oramino group protected with P⁴ into an active ester, mixed acidanhydride, or the like and reacting it with the compound (10) obtained,the compound (12) can be produced. The reaction conditions, reagents,base, and solvent used for forming a peptide bond between the amino acidor peptide (11) and the compound (10) can be suitably selected fromthose described for the synthesis of the compound (6). The protectinggroups P³ and P⁴ can be suitably selected from those described for theprotecting group for the amino group, carboxy group, or hydroxy group ofthe compound (6). However, in such case, it is necessary that theprotecting group P³ for an amino group and the protecting group P⁴ for aside chain functional group can be removed by a different method ordifferent conditions. For example, a representative example includes acombination in which P³ is a 9-fluorenylmethyloxycarbonyl group and P⁴is a tert-butyl group or the like for a carboxy group, a methoxymethylgroup or the like for a hydroxy group, or a tert-butyloxycarbonyl groupor the like for an amino group. The protecting group P⁴ for a side chainfunctional group is preferably a protecting group that can bedeprotected under acidic conditions, but it is not limited thereto, andcan be selected from the aforementioned ones depending on, e.g., theproperties of the compound having an amino group, carboxy group, orhydroxy group to be protected. For removal of the protecting groups,reagents and conditions can be selected depending on the protectinggroup. As it is generally used for peptide synthesis, by repeatingsequentially the reaction and deprotection of the constituting aminoacid or peptide for elongation, the compound (12) can be also produced.

By deprotecting P³ as the protecting group for the terminal amino groupof the compound (12) obtained, the compound (13) can be produced.Reagents and conditions can be selected depending on the protectinggroup.

By derivatizing the carboxylic acid derivative (14) or (14b) into anactive ester, mixed acid anhydride, acid halide, or the like andreacting it with the compound (13) obtained, the compound (15) or (15b)can be produced. Here, the carboxylic acid derivative (14) is a compoundhaving a structure of L¹′ in which the linker terminal is a maleimidylgroup or a haloacetyl group, and the carboxylic acid derivative (14b) isa compound having a structure of L¹′ in which the linker terminal has(Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—.

The reaction conditions, reagents, base, and solvent used for a peptidebond formation between the carboxylic acid derivative (14) or (14b) andthe compound (13) can be suitably selected from those described for thesynthesis of the compound (6).

By deprotecting P⁴ as the protecting group for the amino acid side chaincarboxy group, hydroxy group or amino group of the peptide moiety of thecompound (15) or (15b) obtained, the compound (2) or (2b) can beproduced. Reagents and conditions can be selected depending on theprotecting group.

The compound (9) can be also produced by the following method, forexample.

By derivatizing the peptide or amino acid (8) having the N terminalprotected with P² into active ester, mixed acid anhydride, or the likeand reacting it with the amine compound (16) having the terminal carboxygroup protected with P⁵ in the presence of a base, the compound (17) canbe produced. The reaction conditions, reagents, base, and solvent usedfor forming a peptide bond between the peptide or amino acid (8) and thecompound (16) can be suitably selected from those described for thesynthesis of the compound (6). The protecting group P² for the aminogroup of the compound (17) can be suitably selected from those describedfor the protecting group of the compound (6). As for the protectinggroup P⁵ for a carboxy group, a protecting group commonly used as aprotecting group for a carboxy group in organic synthetic chemistry, inparticular, peptide synthesis can be used. Specifically, it can besuitably selected from those described for the protecting group of thecompound (6), for example, esters with an alkyl group such as a methylgroup, an ethyl group, or a tert-butyl, allyl esters, and benzyl esters.In such case, it is necessary that the protecting group P² for an aminogroup and the protecting group P⁵ for a carboxy group can be removed bya different method or different conditions. For example, arepresentative example includes a combination in which P² is atert-butyloxy carbonyl group and P⁵ is a benzyl group. The protectinggroups can be selected from the aforementioned ones depending on, e.g.,the properties of a compound having an amino group and a carboxy groupto be protected. For removal of the protecting groups, reagents andconditions can be selected depending on the protecting group.

By deprotecting the protecting group P⁵ for the carboxy group of thecompound (17) obtained, the compound (18) can be produced. Reagents andconditions are selected depending on the protecting group.

By derivatizing the compound (18) obtained into active ester, mixed acidanhydride, acid halide, or the like and reacting with the compound (4)in the presence of a base, the compound (9) can be produced. For thereaction, reaction reagents and conditions that are generally used forpeptide synthesis can be also used, and the reaction conditions,reagents, base, and solvent used for the reaction can be suitablyselected from those described for the synthesis of the compound (6).

The compound (12) can be also produced by the following method, forexample.

By deprotecting the protecting group P² for the amino group of thecompound (17), the compound (19) can be produced. Reagents andconditions can be selected depending on the protecting group.

By derivatizing the amino acid or peptide (11) into active ester, mixedacid anhydride, acid halide, or the like and reacting it with thecompound (19) obtained in the presence of a base, the compound (20) canbe produced. The reaction conditions, reagents, base, and solvent usedfor forming an amide bond between the amino acid or peptide (11) and thecompound (19) can be suitably selected from those described for thesynthesis of the compound (6). Here, it is necessary that the protectinggroups P³ and P⁴ of the amino acid or peptide (11) and the protectinggroup P⁵ of the compound (19) can be removed by a different method ordifferent conditions. For example, a representative example includes acombination in which P³ is a 9-fluorenylmethyloxycarbonyl group, P⁴ is atert-butyloxycarbonyl group, tert-butyl group, or methoxymethyl group,and P⁵ is a benzyl group. As mentioned above, the protecting group P⁴for a side chain functional group is preferably a protecting group thatcan be deprotected under acidic conditions, but it is not limitedthereto, and can be selected from the aforementioned ones depending on,e.g., the properties of the compound having an amino group, carboxygroup, or hydroxy group to be protected. For removal of the protectinggroups, reagents and conditions can be selected depending on theprotecting group.

By deprotecting the protecting group P⁵ for the carboxy group of thecompound (20) obtained, the compound (21) can be produced. Reagents andconditions can be selected depending on the protecting group.

By derivatizing the compound (21) into active ester, mixed acidanhydride, acid halide, or the like and reacting it with the compound(4) in the presence of a base, the compound (12) can be produced. Forthe reaction, reaction reagents and conditions that are generally usedfor peptide synthesis can be also used, and the reaction conditions,reagents, base, and solvent used for the reaction can be suitablyselected from those described for the synthesis of the compound (6).

The compound (15) can be also produced by the following method, forexample.

By deprotecting the protecting group P³ for the amino group of thecompound (20), the compound (22) can be produced. Reagents andconditions can be selected depending on the protecting group.

By derivatizing the carboxylic acid derivative (14) into active ester,mixed acid anhydride, acid halide, or the like and reacting it with thecompound (22) obtained in the presence of a base, the compound (23) canbe produced. The reaction conditions, reagents, base, and solvent usedfor forming an amide bond between the carboxylic acid derivative (14)and the compound (22) can be suitably selected from those described forthe synthesis of the compound (6).

By deprotecting the protecting group P⁵ for the carboxy group of thecompound (23) obtained, the compound (24) can be produced. Reagents andconditions can be selected depending on the protecting group.

The compound (15) can be produced by derivatizing the compound (24) intoactive ester, mixed acid anhydride, acid halide, or the like andreacting it with the compound (4) in the presence of a base. For thereaction, reaction reagents and conditions that are generally used forpeptide synthesis can be also used, and the reaction conditions,reagents, base, and solvent used for the reaction can be suitablyselected from those described for the synthesis of the compound (6).

The compound (15) can be also produced by the following method, forexample.

By derivatizing the carboxylic acid derivative (14) into active ester,mixed acid anhydride, acid halide, or the like and reacting it with theamino acid or peptide (25) having a carboxy group protected with P⁶ anda side chain carboxy group, hydroxy group, or amino group protected withP⁴ in the presence of a base, the compound (26) can be produced. Thereaction conditions, reagents, base, and solvent used for forming anamide bond between the carboxylic acid derivative (14) and the compound(25) can be suitably selected from those described for the synthesis ofthe compound (6). Here, the protecting groups P⁴ and P⁶ of the compound(26) can be suitably selected from those described for the protectinggroup for the carboxy group, hydroxy group, or amino group of thecompound (6). However, in such case, it is necessary that the protectinggroup P⁶ for a carboxy group and the protecting group P⁴ for a sidechain functional group can be removed by a different method or differentconditions. For example, a representative example includes a combinationin which P⁶ is a benzyl group and P⁴ is a tert-butyl group or the likefor a carboxy group, a methoxymethyl group or the like for a hydroxygroup, or a tert-butyloxycarbonyl group or the like for an amino group.The protecting group P⁴ for a side chain functional group is preferablya protecting group that can be deprotected under acidic conditions, butit is not limited thereto, and can be selected from the aforementionedones depending on, e.g., the properties of the compound having an aminogroup, carboxy group, or hydroxy group to be protected. For removal ofthe protecting groups, reagents and conditions can be selected dependingon the protecting group.

By deprotecting the protecting group P⁶ for the carboxy group of thecompound (26) obtained, the compound (27) can be produced. Reagents andconditions can be selected depending on the protecting group.

By derivatizing the compound (27) into active ester, mixed acidanhydride, acid halide, or the like and reacting it with the compound(10) in the presence of a base, the compound (15) can be produced. Forthe reaction, reaction reagents and conditions that are generally usedfor peptide synthesis can be also used, and the reaction conditions,reagents, base, and solvent used for the reaction can be suitablyselected from those described for the synthesis of the compound (6).

By derivatizing the compound (27) into active ester, mixed acidanhydride, acid halide, or the like and reacting it with the amino acidor peptide (28) having a carboxy group protected with P⁷ in the presenceof a base, the compound (29) can be produced. For the reaction, reactionreagents and conditions that are generally used for peptide synthesiscan be also used, and the reaction conditions, reagents, base, andsolvent used for the reaction can be suitably selected from thosedescribed for the synthesis of the compound (6). Here, the protectinggroups P⁴ and P⁷ of the compound (29) can be suitably selected fromthose described for the protecting group for the carboxy group, hydroxygroup, or amino group of the compound (6). However, in such case, it isnecessary that the protecting group P⁷ for a carboxy group and theprotecting group P⁴ for a side chain functional group can be removed bya different method or different conditions. For example, arepresentative example includes a combination in which P⁷ is a benzylgroup and P⁴ is a tert-butyl group or the like for a carboxy group, amethoxymethyl group or the like for a hydroxy group, or atert-butyloxycarbonyl group or the like for an amino group. Theprotecting group P⁴ for a side chain functional group is preferably aprotecting group that can be deprotected under acidic conditions, but itis not limited thereto, and can be selected from the aforementioned onesdepending on, e.g., the properties of the compound having an aminogroup, carboxy group, or hydroxy group to be protected. For removal ofthe protecting groups, reagents and conditions can be selected dependingon the protecting group. By repeating sequentially the reaction anddeprotection of the constituting amino acid or peptide for elongation,the compound (29) can be also produced.

By deprotecting the protecting group P⁷ for the carboxy group of thecompound (29) obtained, the compound (30) can be produced. Reagents andconditions can be selected depending on the protecting group.

By derivatizing the compound (30) into active ester, mixed acidanhydride, acid halide, or the like and reacting it with the compound(7) in the presence of a base, the compound (15) can be produced. Forthe reaction, reaction reagents and conditions that are generally usedfor peptide synthesis can be also used, and the reaction conditions,reagents, base, and solvent used for the reaction can be suitablyselected from those described for the synthesis of the compound (6).

The compound (29) can be also produced by the following method, forexample.

By derivatizing the amino acid or peptide (28) into active ester, mixedacid anhydride, acid halide, or the like and reacting it with the aminoacid or peptide (11) having the N terminal protected with P³ and a sidechain carboxy group, hydroxy group, or amino group protected with P⁴ inthe presence of a base, the peptide (31) can be produced. The reactionconditions, reagents, base, and solvent used for forming a peptide bondbetween the amino acid or peptide (28) and the amino acid or peptide(11) can be suitably selected from those described for the synthesis ofthe compound (6). Here, as mentioned above, it is necessary that theprotecting group P⁷ for the carboxy group of the amino acid or peptide(28) and the protecting groups P³ and P⁴ of the amino acid or peptide(11) can be removed by a different method or different conditions. Forexample, a representative example includes a combination in which P³ isa 9-fluorenylmethyloxycarbonyl group, P⁴ is a tert-butyl group or thelike for a carboxy group, a methoxymethyl group or the like for ahydroxy group, or a tert-butyloxycarbonyl group or the like for an aminogroup, and P⁷ is a benzyl group. The protecting group P⁴ for a sidechain functional group is preferably a protecting group that can bedeprotected under acidic conditions, but it is not limited thereto, andcan be selected from the aforementioned ones depending on, e.g., theproperties of the compound having an amino group, carboxy group, orhydroxy group to be protected. For removal of the protecting groups,reagents and conditions can be selected depending on the protectinggroup.

By deprotecting P³ as the protecting group for the N-terminal of thepeptide (31) obtained, the peptide (32) can be produced. Reagents andconditions can be selected depending on the protecting group.

By derivatizing the carboxylic acid derivative (14) into active ester,mixed acid anhydride, acid halide, or the like and reacting it with thepeptide (32) obtained in the presence of a base, the compound (29) canbe produced. The reaction conditions, reagents, base, and solvent usedfor forming an amide bond between the carboxylic acid derivative (14)and the peptide (32) can be suitably selected from those described forthe synthesis of the compound (6).

The compound (12) can be also produced by the following method, forexample.

By deprotecting P⁷ as the protecting group for the C terminal of thepeptide (31), the peptide (33) can be produced. Reagents and conditionscan be selected depending on the protecting group.

By derivatizing the peptide (33) obtained into active ester, mixed acidanhydride, acid halide, or the like and reacting it with the compound(7) in the presence of a base, the compound (12) can be produced. Thereaction conditions, reagents, base, and solvent used for forming anamide bond between the peptide (33) and the compound (7) can be suitablyselected from those described for the synthesis of the compound (6).

5. Production Method 5

Among the production intermediate represented by the formula (2) or (2b)in which the linker has a structure represented by -L¹-L²-L^(P)-, andL^(P) is a peptide residue having a hydrophilic amino acid other thanglycine at the N terminal can be also produced by the following method.

In the formula, L¹′ represents L¹ structure in which the terminal is amaleimidyl group or a haloacetyl group, or L¹ is converted to(Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—(CH₂)n⁵-C(═O)—, L^(P) represents astructure of -L^(p1)-L^(p2)-, and P², P³, P⁴, and P⁷ each represent aprotecting group.

Since L^(P) is formed by connecting L^(p1) and L^(p2), the N-terminalhydrophilic amino acid of L^(P) is derived from L^(p1), therefore,L^(p1) having a hydrophilic amino acid at the N terminal can beemployed. L^(P) may have a plurality of hydrophilic amino acids. IfL^(p2) having a hydrophilic amino acid is used, according to theposition thereof, L^(P) can be produced so as to contain hydrophilicamino acids at the N terminal of L^(P) or at the N terminal and otherpositions.

By derivatizing the peptide or amino acid (8) described in Productionmethod 4 having the N terminal protected with P² into an active ester,mixed acid anhydride, or the like and reacting it with the compound (4)or a salt thereof, the compound (34) can be produced. The reactionconditions, reagents, base, and solvent used for forming a peptide bondbetween the peptide or amino acid (8) and the compound (4) are notlimited as long as they do not inhibit a reaction, and can be suitablyselected from those described for the synthesis of the compound (6). Theprotecting group P² can be suitably selected from those described forthe protecting group of the compound (6), and the selection can be madebased on, e.g., the properties of the compound having an amino group tobe protected. As it is generally used for peptide synthesis, byrepeating sequentially the reaction and deprotection of the amino acidor peptide constituting the peptide or amino acid (8) for elongation,the compound (34) can be also produced.

By deprotecting P² as the protecting group for the amino group of thecompound (34) obtained, the compound (35) can be produced. Reagents andconditions can be selected depending on the protecting group.

By derivatizing the amino acid or peptide (11) described in Productionmethod 4 having the N terminal protected with P³ and a side chaincarboxy group, hydroxy group, or amino group protected with P⁴ into anactive ester, mixed acid anhydride, or the like and reacting it with thecompound (35) obtained, the compound (36) can be produced. The reactionconditions, reagents, base, and solvent used for forming a peptide bondbetween the amino acid or peptide (11) and the compound (35) can besuitably selected from those described for the synthesis of the compound(6). The protecting groups P³ and P⁴ are as described in Productionmethod 4. As it is generally used for peptide synthesis, by repeatingsequentially the reaction and deprotection of the constituting aminoacid or peptide for elongation, the compound (36) can be also produced.

By deprotecting P³ as the protecting group for the amino group of thecompound (36) obtained, the compound (37) can be produced. Reagents andconditions can be selected depending on the protecting group.

By derivatizing the carboxylic acid derivative (14) or (14b) into activeester, mixed acid anhydride, acid halide, or the like and reacting itwith the compound (37) obtained, the compound (38) or (38b) can beproduced. The reaction conditions, reagents, base, and solvent used forforming a peptide bond between the carboxylic acid derivative (14) or(14b) and the compound (37) can be suitably selected from thosedescribed for the synthesis of the compound (6).

By deprotecting P⁴ as the protecting group for the carboxy group orhydroxy group, or amino group of the compound (38) or (38b) obtained,the compound (2) or (2b) can be produced. Reagents and conditions can beselected depending on the protecting group.

The compound (36) can be also produced by the following method, forexample.

By derivatizing the peptide (33) described in Production method 4 intoactive ester, mixed acid anhydride, acid halide, or the like andreacting it with the compound (4) or a salt thereof, the compound (36)can be produced. The reaction conditions, reagents, base, and solventused for forming a peptide bond between the peptide (33) and thecompound (4) can be suitably selected from those described for thesynthesis of the compound (6).

The compound (38) can be also produced by the following method, forexample.

The compound (38) can be produced by derivatizing the compound (30)described in Production method 4 into an active ester, mixed acidanhydride, or the like and reacting it with the compound (4) in thepresence of a base, or by derivatizing the amino acid or peptide (27)described in Production method 4 into an active ester, mixed acidanhydride, or the like and reacting it with the compound (35) in thepresence of a base. The reaction conditions, reagents, base, and solventused for forming a peptide bond can be suitably selected from thosedescribed for the synthesis of the compound (6).

6. Production Method 6

Among the production intermediate represented by the formula (2), thosewhich have a structure of -L¹-L²-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- or-L¹-L²-L^(P)-, and L^(P) is a peptide residue having a hydrophilic aminoacid other than glycine at the N terminal can be also produced by thefollowing method, for example.

In the formula, L¹′ represents L¹ structure in which the terminal is amaleimidyl group or a haloacetyl group, or L¹ is converted to(Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—(CH₂)n⁵-C(═O)—, L^(P) represents astructure of -L^(p1)-L^(p2)-, and P³ and P⁸ each represent a protectinggroup.

The production intermediate represented by the formula (2) has two formsof the linker: a structure represented by-L¹-L²-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- and a structure representedby -L¹-L²-L^(P)-.

The compound (2) in which the linker has the structure represented by-L¹-L²-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- can be produced as follows.

The compound (40) can be synthesized in the same manner as in thecompound (12) described in Production method 4. Unlike the compound(12), it may be unnecessary that the protecting group P³ for an aminogroup and the protecting group P⁸ for a side chain functional group canbe removed by a different method or different conditions. The functionalgroup of the side chain is a carboxy group or a hydroxy group, and theprotecting group P³ for an amino group and the protecting group P⁸ for aside chain carboxy group or hydroxy group can be deprotectedsimultaneously. For example, a representative example includes acombination in which P³ is a tert-butyloxycarbonyl group, and P⁸ is atert-butyl group or a trityl group, or P³ is a benzyloxycarbonyl group,and P⁸ is a benzyl group. These protecting groups can be suitablyselected from those described for the protecting group of the compound(6) depending on, e.g., the properties of the compound having an aminogroup, carboxy group, or hydroxy group to be protected. For removal ofthe protecting groups, reagents and conditions can be selected dependingon the protecting group. The compound (40) can be synthesized in thesame manner as Production method 4 by using the protected amino acid orpeptide that satisfies the properties described above.

By sequentially or simultaneously deprotecting the protecting groups P³and P⁸ of the compound (40), the compound (41) can be produced. Reagentsand conditions can be selected depending on the protecting group.

Although the functional group in the hydrophilic side chain of L^(P) inthe compound (41) is not particularly protected, the compound (2) can beproduced by reacting it with the compound (14) or (14b) derivatized intoan active ester, mixed acid anhydride, or the like in the presence of abase. The reaction conditions, reagents, base, and solvent used for apeptide bond formation can be suitably selected from those described forthe synthesis of the compound (6).

The compound (2) in which the linker has the structure represented by-L¹-L²-L^(P)- can be produced as follows.

The compound (42) can be also synthesized as in the same manner as thecompound (36) described in Production method 5. Unlike the compound(36), it may be unnecessary that the protecting group P³ for an aminogroup and the protecting group P⁸ for the functional group of the sidechain can be removed by a different method or different conditions. Thefunctional group of the side chain is a carboxy group or a hydroxygroup, and the protecting group P³ for an amino group and the protectinggroup P⁸ for a side chain carboxy group or hydroxy group can be alsodeprotected simultaneously. For example, a representative exampleincludes a combination in which P³ is a tert-butyloxycarbonyl group, andP⁸ is a tert-butyl group or a trityl group, or P³ is a benzyloxycarbonylgroup, and P⁸ is a benzyl group. These protecting groups can be suitablyselected from those described for the protecting group of the compound(6) depending on, e.g., the properties of the compound having an aminogroup, carboxy group, or hydroxy group to be protected. For removal ofthe protecting groups, reagents and conditions can be selected dependingon the protecting group. The compound (42) can be synthesized in thesame manner as Production method 5 by using the protected amino acid orpeptide that satisfies the properties described above.

By sequentially or simultaneously deprotecting the protecting groups P³and P⁸ of the compound (42), the compound (43) can be produced. Reagentsand conditions can be selected depending on the protecting group.

Although the functional group in the hydrophilic side chain of L^(P) inthe compound (43) is not particularly protected, the compound (2) can beproduced by reacting it with the compound (14) or (14b) derivatized intoan active ester, mixed acid anhydride, or the like in the presence of abase. The reaction conditions, reagents, base, and solvent used forforming a peptide bond can be suitably selected from those described forthe synthesis of the compound (6).

7. Production Method 7

The compound (36) shown in Production method 5 in which linker -L^(P)-has a structure of -L^(p1)-Gly-Gly-Phe-Gly-can be also produced by thefollowing method.

In the formula, L¹′ represents L¹ structure in which the terminal is amaleimidyl group or a haloacetyl group, or L¹ is converted to(Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—(CH₂)n⁵-C(═O)—, -L^(P)- representsa structure of -L^(p1)-Gly-Gly-Phe-Gly-, and P³ and P⁴ each represent aprotecting group.

The compound (45) can be produced by derivatizing the amino acid orpeptide (11) described in Production method 4 into active ester, mixedacid anhydride, acid halide, or the like and reacting it withglycylglycyl-L-phenylalanyl-N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolidino[1,2-b]quinolin-1-yl]glycineamide(that is, a free form of the pharmaceutical compound described inWO97/46260) (44) or a salt thereof in the presence of a base. Thereaction conditions, reagents, base, and solvent used for forming apeptide bond between the amino acid or peptide (11) and the compound(44) can be suitably selected from those described for the synthesis ofthe compound (6). The protecting group P³ for the N-terminal and theprotecting group P⁴ for a side chain functional group are as mentionedabove in Production method 4. The protecting group P⁴ for a side chainfunctional group may be absent, and the compound (45) can be obtained bythe reaction using the amino acid or peptide (11) protected only at theN-terminal.

8. Production Method 8

Among the compound represented by the formula (2) or (2b), those whichhave the linker structure represented by -L¹-L²-L^(P)-, and L^(P) is apeptide residue in which the C terminal is an oligopeptide consisting of2 or 3 or more glycines and is connected to the drug, and even in casethat a hydrophilic amino acid is present at N terminal, no otherhydrophilic amino acid than glycine is present thereat, can be alsoproduced by the following method, for example.

In the formula, L¹′ represents L¹ structure in which the terminal is amaleimidyl group or a haloacetyl group, or L¹ is converted to(Pyrrolidine-2,5-dione-N-yl)-O—C(═O)—(CH₂)n⁵-C(═O)—, L^(P) represents astructure of -L^(p1)-L^(p2)-, and P⁷ and P⁹ each represent a protectinggroup.

Since L^(P) is formed by connecting L^(p1) and L^(p2), the number ofglycines contained therein for constituting the C terminal of L^(P) canbe determined by considering the number of C-terminal glycines of L^(P)and further, the number of repetitive uses thereof for the reaction.

The peptide (46) is an oligopeptide in which the C terminal isconsisting of 2 or 3 or more glycines, and in case when the N terminalis optionally a hydrophilic amino acid but it is not a hydrophilic aminoacid other than glycine, and this N terminal is protected with P⁹. Thepeptide (46) can be synthesized by repeating sequentially thecondensation reaction and deprotection of the amino acid or peptideconstituting it, as it is generally used for peptide synthesis.

By derivatizing the peptide (46) into an active ester, mixed acidanhydride, or the like and reacting it with the compound (4) or a saltthereof, the compound (47) can be produced. The reaction conditions,reagents, base, and solvent used for forming a peptide bond between thepeptide (46) and the compound (4) can be suitably selected from thosedescribed for the synthesis of the compound (6). The protecting group P⁹can be suitably selected from those described for the synthesis of thecompound (6).

The compound (47) can be also produced by derivatizing the amino acid orpeptide (48) having the N terminal protected with P⁹ into an activeester, mixed acid anhydride, or the like and reacting it with thecompound (35) described in Production method 5. The reaction conditions,reagents, base, and solvent used for forming a peptide bond between theamino acid or peptide (48) and the compound (35) can be suitablyselected from those described for the synthesis of the compound (6). Theprotecting group P⁹ can be suitably selected from those described forthe synthesis of the compound (6).

By deprotecting the protecting group P⁹ for the amino group of thecompound (47) obtained, the compound (49) can be produced. Reagents andconditions can be selected depending on the protecting group.

By derivatizing the carboxylic acid derivative (14) or (14b) into activeester, mixed acid anhydride, acid halide, or the like and reacting itwith the compound (49) obtained, the compound (2) or (2b) can beproduced. The reaction conditions, reagents, base, and solvent used forforming an amide bond between the carboxylic acid derivative (14) or(14b) and the compound (49) can be suitably selected from thosedescribed for the synthesis of the compound (6).

The compound (2) can be also produced by the following method.

The compound (50) in which the N-terminal glycine of L^(p1) is connectedto L² can be synthesized as in the same manner as the compound (27)described in Production method 4. By derivatizing the amino acid orpeptide (28) described in Production method 4 into active ester, mixedacid anhydride, acid halide, or the like and reacting it with thecompound (50), the compound (51) can be produced. Here, the amino acidor peptide (28) is glycine or an oligopeptide having the C-terminalconsisting of 2 or 3 or more glycines, and its C terminal is protectedwith P⁷. The reaction conditions, reagents, base, and solvent used forforming an amide bond between the amino acid or peptide (28) and thecompound (50) can be suitably selected from those described for thesynthesis of the compound (6).

The compound (51) can be also produced by derivatizing the compound (14)into an active ester, mixed acid anhydride, or the like and reacting itwith the peptide (52) having the C terminal protected with P⁷. Here, thepeptide (52) is an oligopeptide in which the C terminal is consisting of2 or 3 or more glycines, and the N terminal is optionally a hydrophilicamino acid but no other hydrophilic amino acid than glycine is presentthereat. The peptide (52) can be synthesized by repeating sequentiallythe condensation reaction and deprotection of the amino acid or peptideconstituting it, as it is generally used for peptide synthesis. Thereaction conditions, reagents, base, and solvent used for forming apeptide bond between the peptide (52) and the compound (14) can besuitably selected from those described for the synthesis of the compound(6). The protecting group P⁷ is preferably a protecting group that canbe deprotected under acidic conditions, but it is not limited thereto,and can be suitably selected from those described for the synthesis ofthe compound (6).

By deprotecting the protecting group P⁷ for the carboxy group of thecompound (51) obtained, the compound (53) can be produced. Reagents andconditions can be selected depending on the protecting group.

The compound (2) can be produced by derivatizing the compound (53) intoan active ester, mixed acid anhydride, or the like and reacting it withthe compound (4) or a salt thereof. The reaction conditions, reagents,base, and solvent used for forming a peptide bond between the compound(53) and the compound (4) can be suitably selected from those describedfor the synthesis of the compound (6).

Alternatively, the compound (2) can be also produced by the followingmethod.

The compound (2) can be produced by derivatizing the compound (35)described in Production method 5 into an active ester, mixed acidanhydride, or the like and reacting it with the compound (50) in thepresence of a base. The reaction conditions, reagents, base, and solventused for forming a peptide bond between the compound (50) and thecompound (35) can be suitably selected from those described for thesynthesis of the compound (6).

9. Production Method 9

The production intermediate represented by the formula (2a) described inProduction method 2 in which L²′ corresponds to L² having a structure inwhich the terminal is converted to a mercaptoalkanoyl group can beproduced by the following method.

In the formula, L^(P) represents a structure of L^(p1)-L^(p2), and P⁴,P⁵, P⁷, and P¹⁰ each represents a protecting group.

The production intermediate represented by the formula (2a) has twoforms of the linker: a structure represented by-L¹-L²-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- and a structure representedby -L¹-L²-L^(P)-.

The compound (2a) in which the linker has the structure represented by-L¹-L²-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- can be produced as follows.

The compound (55) can be produced by derivatizing the carboxylic acidcompound (54) having a terminal mercapto group protected with P¹⁰ intoan active ester, mixed acid anhydride, or the like and reacting it withthe compound (13) described in Production method 4. For the reaction,reaction reagents and conditions that are generally used for peptidesynthesis can be also used, and the reaction conditions, reagents, base,and solvent used for the reaction can be suitably selected from thosedescribed for the synthesis of the compound (6). As for the protectinggroup P¹⁰ for a mercapto group, a protecting group commonly used as aprotecting group for a mercapto group in organic synthetic chemistry canbe used. Specifically, it can be suitably selected from sulfide groupssuch as a S-methyl sulfide group, a S-ethyl sulfide group, and aS-2-pyridyl sulfide group, ester groups such as an acetyl group, arylmethyl ether groups such as a benzyl group, a 9-fluorenylmethyl group,and a trityl group, ethyl ether groups such as a S-2-cyanoethyl group,and the like. In this case, the protecting group P⁴ for the side chainamino group, carboxy group, or hydroxy group of L^(p1) is preferably aprotecting group that can be deprotected under acidic conditions, but itis not limited thereto, and can be selected from the aforementioned onesdepending on, e.g., the properties of the compound having an aminogroup, carboxy group, or hydroxy group to be protected. However, it isnecessary that the protecting group P¹⁰ for a mercapto group and theprotecting group P⁴ for the side chain carboxy group, hydroxy group, oramino group of L^(p1) can be removed by a different method or differentconditions. For example, a representative example includes a combinationin which the protecting group P⁴ is a tert-butyl group for a carboxygroup, and the protecting group P¹⁰ is a S-methyl sulfide group. Theprotecting group P¹⁰ may be absent. In this case, the mercapto group ofthe compound (55) is unprotected.

By deprotecting the protecting group P⁴ for the side chain carboxygroup, hydroxy group, or amino group of L^(p1) in the compound (55)obtained, the compound (56) can be produced. Reagents and conditions canbe selected depending on the protecting group.

By deprotecting the protecting group P¹⁰ for the mercapto group of thecompound (56) obtained, the compound (2a) can be produced. Reagents andconditions can be selected depending on the protecting group.

The compound (55) can be also produced by the following method.

The compound (57) can be produced by derivatizing the carboxylic acidcompound (54) having a mercapto group protected with P¹⁰ into activeester, mixed acid anhydride, acid halide, or the like and reacting itwith the compound (22) described in Production method 4. For thereaction, reaction reagents and conditions that are generally used forpeptide synthesis can be also used, and the reaction conditions,reagents, base, and solvent used for the reaction can be suitablyselected from those described for the synthesis of the compound (6). Theprotecting groups P⁴ and P¹⁰ are as mentioned above. The protectinggroup P⁵ for a carboxy group can be suitably selected from thosedescribed for the protecting group of the compound (6). However, it isnecessary that the protecting group P¹⁰ for a mercapto group and theprotecting group P⁴ for a side chain functional group can be removed bya different method or different conditions from those for the protectinggroup P⁵ for a carboxy group. For example, a representative exampleincludes a combination in which P⁴ is a tert-butyl group for a carboxygroup, P¹⁰ is a S-methyl sulfide group, and P⁵ is an allyl group. Theprotecting group P¹⁰ may be absent. In this case, the mercapto group ofthe compound (57) is unprotected.

The compound (58) can be produced by deprotecting the protecting groupP⁵ for the carboxy group of the compound (57) obtained. Reagents andconditions can be selected depending on the protecting group.

The compound (55) can be produced by derivatizing the compound (58) intoactive ester, mixed acid anhydride, acid halide, or the like andreacting it with the compound (4) in the presence of a base. For thereaction, reaction reagents and conditions that are generally used forpeptide synthesis can be also used, and the reaction conditions,reagents, base, and solvent used for the reaction can be suitablyselected from those described for the synthesis of the compound (6).

The compound (2a) in which the linker has the structure represented byL¹-L²-L^(P)-, and L^(P) is a peptide residue having a hydrophilic aminoacid other than glycine at the N terminal can be produced as follows.

The compound (59) can be produced by derivatizing the carboxylic acidcompound (54) having a mercapto group protected with P¹⁰ into activeester, mixed acid anhydride, acid halide, or the like and reacting itwith the compound (37) described in Production method 5. For thereaction, reaction reagents and conditions that are generally used forpeptide synthesis can be also used, and the reaction conditions,reagents, base, and solvent used for the reaction can be suitablyselected from those described for the synthesis of the compound (6). Theprotecting groups P⁴ and P¹⁰ are as mentioned above.

The compound (59) can be also produced by the following method, forexample.

The compound (60) can be produced by derivatizing the carboxylic acidcompound (54) having a mercapto group protected with P¹⁰ into activeester, mixed acid anhydride, or the like and reacting it with thecompound (32) described in Production method 4. For the reaction,reaction reagents and conditions that are generally used for peptidesynthesis can be also used, and the reaction conditions, reagents, base,and solvent used for the reaction can be suitably selected from thosedescribed for the synthesis. The protecting groups P⁴, P⁷, and P¹⁰ areas mentioned above and can be suitably selected from those described forthe protecting group of the compound (6). However, it is necessary thatthe protecting group P¹⁰ for a mercapto group and the protecting groupP⁴ for a side chain functional group can be removed by a differentmethod or different conditions from those for the protecting group P⁷for a carboxy group. For example, a representative example includes acombination in which P⁴ is a tert-butyl group for a carboxy group, P¹⁰is a S-methyl sulfide group, and P⁷ is an allyl group. The protectinggroup P¹⁰ may be absent. In this case, the mercapto group of thecompound (60) is unprotected.

By deprotecting the protecting group P⁷ for the carboxy group of thepeptide in the compound (60) obtained, the compound (61) can beproduced. Reagents and conditions can be selected depending on theprotecting group.

The compound (59) can be produced by derivatizing the compound (61)obtained into active ester, mixed acid anhydride, acid halide, or thelike and reacting it with the compound (4) or a salt thereof in thepresence of a base. For the reaction, reaction reagents and conditionsthat are generally used for peptide synthesis can be also used, and thereaction conditions, reagents, base, and solvent used for the reactioncan be suitably selected from those described for the synthesis of thecompound (6).

By deprotecting the protecting group P⁴ for the carboxy group of L^(P)′in the compound (59) obtained, the compound (62) can be produced.Reagents and conditions can be selected depending on the protectinggroup.

By deprotecting the protecting group P¹⁰ for the mercapto group of thecompound (62) obtained, the compound (2a) can be produced. Reagents andconditions can be selected depending on the protecting group.

The compound (2a) in which the linker has the structure represented by-L¹-L²-L^(P)-, and L^(P) is a peptide residue in which the C terminal isan oligopeptide consisting of 2 or 3 or more glycines and is connectedto the drug, and even in case when a hydrophilic amino acid is presentat N terminal, no other hydrophilic amino acid than glycine is presentthereat, can be produced as follows.

The compound (2a) can be produced by derivatizing the carboxylic acidcompound (54) into active ester, mixed acid anhydride, or the like andreacting it with the compound (49) described in Production method 8.Here, the mercapto group may not be protected with P¹⁰. For thereaction, reaction reagents and conditions that are generally used forpeptide synthesis can be also used, and the reaction conditions,reagents, base, and solvent used for the reaction can be suitablyselected from those described for the synthesis of the compound (6).

10. Production Method 10

Among the production intermediate represented by the formula (2), L¹′ inwhich L¹ is converted to have a structure of terminal(maleimid-N-yl)-CH[—(CH₂)n³-COOH]—C(═O)— can be produced by thefollowing method.

In the formula, P¹¹ and P¹² each represents a protecting group.

The production intermediate represented by the formula (2) has two formsof the linker: a structure represented by-L¹-L²-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- and a structure representedby -L¹-L²-L^(P).

The compound (2) in which the linker has the structure represented by-L¹-L²-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- can be produced as follows.

The (maleimid-N-yl)- compound (65) can be produced by reacting the aminoacid (63) having a protected side chain carboxy group by P¹¹ with theN-methoxycarbonylmaleimide (64) at −40° C. to 100° C. in the presence ofa base such as sodium bicarbonate in water. The maleimidyl compound canbe synthesized from a compound having an amino group by a method knownin the art using N-methoxycarbonylmaleimide (e.g., Keller, 0.; Rudinger,J. Helv. Chem. Acta 1975, 58 (2), 531-541.) or a method equivalentthereto. As for the protecting group P¹¹ for a carboxy group, aprotecting group commonly used as a protecting group for a carboxy groupin organic synthetic chemistry can be used. It is preferably aprotecting group that can be deprotected under acidic conditions, but itis not limited thereto.

The compound (67) can be produced by derivatizing the compound (66)having a terminal amino group protected by P¹² into an active ester,mixed acid anhydride, or the like and reacting it with the compound (41)described in Production method 6 in the presence of a base. The reactionconditions, reagents, base, and solvent used for forming an amide bondbetween the compound (67) and the compound (41) can be suitably selectedfrom those described for the synthesis of the compound (6). Theprotecting group P¹² for the amino group of the compound (66) can besuitably selected from those described for the protecting group of thecompound (6).

By deprotecting the protecting group P¹² for the amino group of thecompound (67) obtained, the compound (68) can be produced. Reagents andconditions can be selected depending on the protecting group.

The compound (69) can be produced by derivatizing the compound (65) intoan active ester, mixed acid anhydride, or the like and reacting it withthe compound (68) obtained in the presence of a base. The reactionconditions, reagents, base, and solvent used for forming an amide bondbetween the compound (65) and the compound (68) can be suitably selectedfrom those described for the synthesis of the compound (6).

By deprotecting the protecting group P¹¹ for the carboxy group of thecompound (69) obtained, the compound (2) can be produced. Reagents andconditions can be selected depending on the protecting group.

The compound (2) in which the linker has the structure represented by-L¹-L²-L^(P)- can be produced as follows.

Similarly, the compound (70) can be produced by derivatizing thecompound (66) having a protected terminal amino group by P¹² into anactive ester, mixed acid anhydride, or the like and reacting it with thecompound (43) described in Production method 6 in the presence of abase. The reaction conditions, reagents, base, and solvent used forforming an amide bond between the compound (66) and the compound (43)can be suitably selected from those described for the synthesis of thecompound (6). The protecting group P¹² is as mentioned above.

By deprotecting the protecting group P¹² for the amino group of thecompound (70) obtained, the compound (71) can be produced. Reagents andconditions can be selected depending on the protecting group.

The compound (72) can be produced by derivatizing the compound (65) intoan active ester, mixed acid anhydride, or the like and reacting it withthe compound (71) obtained in the presence of a base. The reactionconditions, reagents, base, and solvent used for forming an amide bondbetween the compound (65) and the compound (71) can be suitably selectedfrom those described for the synthesis of the compound (6).

By deprotecting the protecting group P^(II) for the carboxy group of thecompound (72) obtained, the compound (2) can be produced. Reagents andconditions can be selected depending on the protecting group.

11. Production Method 11

Among the production intermediate represented by the formula (2), thosehaving L¹′ in which L¹ is converted to have a structure of terminalmaleimidyl group or terminal haloacetyl group, and L² is—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)— can be produced by the followingmethod.

In the formula, P¹³ represents a protecting group, and X represents aleaving group.

The production intermediate represented by the formula (2) has two formsas the linker: a structure represented by-L¹-L²-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- and a structure representedby -L¹-L²-L^(P)-.

The compound (2) in which the linker has the structure represented by-L¹-L²-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- can be produced as follows.

The compound (75) can be produced by reacting the glycine derivative(73) having the protected C terminal by P¹³ with the compound (74) inthe presence of a base. The protecting group P¹³ for a carboxy group ispreferably a protecting group that can be deprotected under acidicconditions, but it is not limited thereto. Examples of the leaving groupX of the compound (74) can include sulfonic acid esters such asp-toluene sulfonate, methyl sulfonate, and trifluoromethyl sulfonate aswell as halides such as iodide, bromide, and chloride. For thisreaction, reaction conditions that are generally used for N-alkylationcan be also used, and the base and solvent used for the reaction can beselected from those described for the synthesis of the compound (6).

The compound (77) can be produced by derivatizing the carboxylic acidderivative (76) into active ester, mixed acid anhydride, acid halide, orthe like and reacting it with the compound (75) obtained. The reactionconditions, reagents, base, and solvent used for forming a peptide bondbetween the carboxylic acid derivative (76) and the compound (75) can besuitably selected from those described for the synthesis of the compound(6).

By deprotecting the protecting group P¹³ for the carboxy group of thecompound (77) obtained, the compound (78) can be produced. Reagents andconditions can be selected depending on the protecting group.

The compound (2) can be produced by derivatizing the compound (78)obtained into active ester, mixed acid anhydride, acid halide, or thelike and reacting it with the compound (41) described in Productionmethod 6. The reaction conditions, reagents, base, and solvent used forforming an amide bond between the carboxylic acid derivative (78) andthe compound (41) can be suitably selected from those described for thesynthesis of the compound (6).

The compound (2) in which the linker has the structure represented by-L¹-L²-L^(P)- can be produced as follows.

Similarly, the compound (2) can be produced by derivatizing the compound(78) into active ester, mixed acid anhydride, acid halide, or the likeand reacting it with the compound (43) described in Production method 6.The reaction conditions, reagents, base, and solvent used for forming anamide bond between the carboxylic acid derivative (78) and the compound(43) can be suitably selected from those described for the synthesis ofthe compound (6).

All of the intermediate compounds of Production methods 1 to 11 may formsalts.

Meanwhile, the antibody-drug conjugate of the present invention, when itis left in air or recrystallized, may absorb moisture to have adsorptionwater or turn into a hydrate, and such a compound and a salt containingwater are also included in the present invention.

A compound labeled with various radioactive or non-radioactive isotopesis also included in the present invention. One or more atomsconstituting the antibody-drug conjugate of the present invention maycontain an atomic isotope at non-natural ratio. Examples of the atomicisotope include deuterium (²H), tritium (³H), iodine-125 (¹²⁵I), andcarbon-13 (¹³C). Further, the compound of the present invention may beradioactive-labeled with a radioactive isotope such as tritium (³H),iodine-125 (¹²⁵I), carbon-14 (¹⁴C), copper-64 (⁶⁴Cu), zirconium-89(⁸⁹Zr), iodine-124 (¹²⁴I), fluorine-18 (¹⁸F), indium-111 (¹¹¹I),carbon-11 (¹¹C) and iodine-131 (¹³¹I). The compound labeled with aradioactive isotope is useful as a therapeutic or prophylactic agent, areagent for research such as an assay reagent and an agent for diagnosissuch as an in vivo diagnostic imaging agent. Without being related toradioactivity, any isotope variant type of the antibody-drug conjugateof the present invention is within the scope of the present invention.

[Drugs]

The antibody-drug conjugate of the present invention exhibits acytotoxic activity against cancer cells, and thus, it can be used as adrug, particularly as a therapeutic agent and/or prophylactic agent forcancer.

Examples of the cancer type to which the antibody-drug conjugate of thepresent invention is applied include lung cancer, kidney cancer,urothelial cancer, colorectal cancer, prostate cancer, glioblastomamultiforme, ovarian cancer, pancreatic cancer, breast cancer, melanoma,liver cancer, bladder cancer, stomach cancer, or esophageal cancer,however, it is not limited to them as long as it is a cancer cellexpressing, in a cancer cell as a treatment subject, a protein which theantibody within the antibody-drug conjugate can recognize.

The antibody-drug conjugate of the present invention can be preferablyadministered to a mammal, but it is more preferably administered to ahuman.

Substances used in a pharmaceutical composition containing antibody-drugconjugate of the present invention can be suitably selected and appliedfrom formulation additives or the like that are generally used in theart, in view of the dosage or administration concentration.

The antibody-drug conjugate of the present invention can be administeredas a pharmaceutical composition containing at least one pharmaceuticallysuitable ingredient. For example, the pharmaceutical composition abovetypically contains at least one pharmaceutical carrier (for example,sterilized liquid). for example, water and oil (petroleum oil and oil ofanimal origin, plant origin, or synthetic origin (the oil may be, forexample, peanut oil, soybean oil, mineral oil, sesame oil or the like)).Water is a more typical carrier when the pharmaceutical compositionabove is intravenously administered. Saline solution, an aqueousdextrose solution, and an aqueous glycerol solution can be also used asa liquid carrier, in particular, for an injection solution. A suitablepharmaceutical vehicle is known in the art. If desired, the compositionabove may also contain a trace amount of a moisturizing agent, anemulsifying agent, or a pH buffering agent. Examples of suitablepharmaceutical carrier are disclosed in “Remington's PharmaceuticalSciences” by E. W. Martin. The formulations correspond to anadministration mode.

Various delivery systems are known and they can be used foradministering the antibody-drug conjugate of the present invention.Examples of the administration route include intradermal, intramuscular,intraperitoneal, intravenous, and subcutaneous routes, but not limitedthereto. The administration can be made by injection or bolus injection,for example. According to a specific preferred embodiment, theadministration of the antibody-drug conjugate is performed by injection.Parenteral administration is a preferred administration route.

According to a representative embodiment, the pharmaceutical compositionis prescribed, as a pharmaceutical composition suitable for intravenousadministration to human, according to the conventional procedures. Thecomposition for intravenous administration is typically a solution in asterile and isotonic aqueous buffer solution. If necessary, the drug maycontain a solubilizing agent and local anesthetics to alleviate pain atinjection site (for example, lignocaine). Generally, the ingredientabove is provided individually as any one of lyophilized powder or ananhydrous concentrate contained in a container which is yielded bysealing in an ampoule or a sachet having an amount of the active agentor as a mixture in a unit dosage form. When the drug is to beadministered by injection, it may be administered from an injectionbottle containing water or saline of sterile pharmaceutical grade. Whenthe drug is administered by injection, an ampoule of sterile water orsaline for injection may be provided such that the aforementionedingredients are admixed with each other before administration.

The pharmaceutical composition of the present invention may be apharmaceutical composition containing only the antibody-drug conjugateof the present invention or a pharmaceutical composition containing theantibody-drug conjugate and at least one cancer treating agent otherthan the conjugate. The antibody-drug conjugate of the present inventioncan be administered with other cancer treating agent. The anti-cancereffect may be enhanced accordingly. Another anti-cancer agent used forsuch purpose may be administered to an individual simultaneously with,separately from, or subsequently to the antibody-drug conjugate, and itmay be administered while varying the administration interval for each.Examples of the cancer treating agent include abraxane, carboplatin,cisplatin, gemcitabine, irinotecan (CPT-11), paclitaxel, pemetrexed,sorafenib, vinorelbine, drugs described in International Publication No.WO 2003/038043, LH-RH analogues (leuprorelin, goserelin, or the like),estramustine phosphate, estrogen antagonist (tamoxifen, raloxifene, orthe like), and an aromatase inhibitor (anastrozole, letrozole,exemestane, or the like), but it is not limited as long as it is a drughaving an antitumor activity.

The pharmaceutical composition can be formulated into a lyophilizationformulation or a liquid formulation as a formulation having desiredcomposition and required purity. When formulated as a lyophilizationformulation, it may be a formulation containing suitable formulationadditives that are used in the art. Also for a liquid formulation, itcan be formulated as a liquid formulation containing various formulationadditives that are used in the art.

Composition and concentration of the pharmaceutical composition may varydepending on administration method. However, the antibody-drug conjugatecontained in the pharmaceutical composition of the present invention canexhibit the pharmaceutical effect even at a small dosage when theantibody-drug conjugate has higher affinity for an antigen, that is,higher affinity (=lower Kd value) in terms of the dissociation constant(that is, Kd value) for the antigen. Thus, for determining dosage of theantibody-drug conjugate, the dosage can be determined in view of asituation relating to the affinity between the antibody-drug conjugateand antigen. When the antibody-drug conjugate of the present inventionis administered to a human, for example, about 0.001 to 100 mg/kg can beadministered once or administered several times with an interval of onetime for 1 to 180 days.

EXAMPLES

The present invention is specifically described in view of the examplesshown below, however, the present invention is not limited to them, andfurther, it is by no means interpreted in a limited sense. Further,unless specifically described otherwise, the reagent, solvent, andstarting material described in the specification can be easily obtainedfrom a commercial supplier.

Reference Example 1 M30-H1-L4 Antibody

Among humanized antibodies of an anti-B7-H3 antibody, an antibodycomposed of a heavy chain consisting of an amino acid sequence describedin amino acid positions 20 to 471 in SEQ ID NO: 9 and a light chainconsisting of an amino acid sequence described in amino acid positions21 to 233 in SEQ ID NO: 16 was produced in accordance with a methodknown in the art. The obtained humanized anti-B7-H3 antibody wasdesignated as an M30-H1-L4 antibody.

Reference Example 2 M30-H1-L4P Antibody

The modification of a glycan linked to the M30-H1-L4 antibody obtainedabove was regulated by defucosylation in accordance with a method knownin the art. The obtained antibody with the regulated modification of aglycan was designated as an M30-H1-L4P antibody.

Reference Example 3 Anti-CD30 Antibody

An anti-CD30 antibody was produced with reference to NationalPublication of International Patent Application No. 2005-506035. Itssequence is shown in SEQ ID NOs: 27 and 28.

Reference Example 4 Anti-CD33 Antibody

An anti-CD33 antibody was produced with reference to Japanese PatentLaid-Open No. 8-48637. Its sequence is shown in SEQ ID NOs: 29 and 30.

Reference Example 5 Anti-CD70 Antibody

An anti-CD70 antibody was produced with reference to NationalPublication of International Patent Application No. 2008-538292. Itssequence is shown in SEQ ID NOs: 31 and 32.

Example 14-Amino-N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]butanamide

Process 1:tert-Butyl(4-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-4-oxobutyl)carbamate

4-(tert-Butoxycarbonylamino)butanoic acid (0.237 g, 1.13 mmol) wasdissolved in dichloromethane (10 mL), charged with N-hydroxysuccinimide(0.130 g, 1.13 mmol) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimidehydrochloride (0.216 g, 1.13 mmol), and stirred for 1 hour. The reactionsolution was added dropwise to an N,N′-dimethylformamide solution (10.0mL) charged with methanesulfonate of the compound (4) (0.500 g, 0.941mmol) and triethylamine (0.157 mL, 1.13 mmol), and stirred at roomtemperature for 1 day. The solvent was removed under reduced pressureand the obtained residues were purified by silica gel columnchromatography [chloroform-chloroform:methanol=8:2 (v/v)] to yield thetitled compound as a deep yellow solid (0.595 g, quantitative).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.87 (3H, t, J=7.2 Hz), 1.31 (9H, s), 1.58(1H, t, J=7.2 Hz), 1.66 (2H, t, J=7.2 Hz), 1.82-1.89 (2H, m), 2.12-2.21(3H, m), 2.39 (3H, s), 2.92 (2H, t, J=6.5 Hz), 3.17 (2H, s), 5.16 (1H,d, J=18.8 Hz), 5.24 (1H, d, J=18.8 Hz), 5.42 (2H, s), 5.55-5.59 (1H, m),6.53 (1H, s), 6.78 (1H, t, J=6.3 Hz), 7.30 (1H, s), 7.79 (1H, d, J=11.0Hz), 8.40 (1H, d, J=8.6 Hz).

MS (APCI) m/z: 621 (M+H)⁺

Process 2:4-Amino-N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]butanamide

The compound (0.388 g, 0.626 mmol) obtained in Process 1 above wasdissolved in dichloromethane (9.00 mL). Trifluoroacetic acid (9.00 mL)was added to be stirred for 4 hours. The solvent was removed underreduced pressure and the obtained residue was purified by silica gelcolumn chromatography [chloroform-partitioned organic layer ofchloroform:methanol:water=7:3:1 (v/v/v)] to yield trifluoroacetate ofthe titled compound as a yellow solid (0.343 g, quantitative).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.87 (3H, t, J=7.2 Hz), 1.79-1.92 (4H, m),2.10-2.17 (2H, m), 2.27 (2H, t, J=7.0 Hz), 2.40 (3H, s), 2.80-2.86 (2H,m), 3.15-3.20 (2H, m), 5.15 (1H, d, J=18.8 Hz), 5.26 (1H, d, J=18.8 Hz),5.42 (2H, s), 5.54-5.61 (1H, m), 6.55 (1H, s), 7.32 (1H, s), 7.72 (3H,brs), 7.82 (1H, d, J=11.0 Hz), 8.54 (1H, d, J=8.6 Hz).

MS (APCI) m/z: 521 (M+H)⁺

Example 2 Antibody-Drug Conjugate (1)

Process 1:N-(tert-butoxycarbonyl)glycylglycyl-L-phenylalanyl-N-(4-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-4-oxobutyl)glycinamide

N-(tert-butoxycarbonyl)glycylglycyl-L-phenylalanylglycine (80.9 g, 0.185mmol) was dissolved in dichloromethane (3.00 mL), charged withN-hydroxysuccinimide (21.3 mg, 0.185 mmol) and1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (35.5 mg,0.185 mmol), and stirred for 3.5 hours. The reaction solution was addeddropwise to an N,N′-dimethylformamide solution (1.50 mL) charged withthe compound (80.4 mg, 0.154 mmol) of Example 1, and stirred at roomtemperature for 4 hours. The solvent was removed under reduced pressureand the obtained residue was purified by silica gel columnchromatography [chloroform-chloroform:methanol=8:2 (v/v)] to yield thetitled compound as a pale yellow solid (0.106 g, 73%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.87 (3H, t, J=7.4 Hz), 1.36 (9H, s), 1.71(2H, m), 1.86 (2H, t, J=7.8 Hz), 2.15-2.19 (4H, m), 2.40 (3H, s), 2.77(1H, dd, J=12.7, 8.8 Hz), 3.02 (1H, dd, J=14.1, 4.7 Hz), 3.08-3.11 (2H,m), 3.16-3.19 (2H, m), 3.54 (2H, d, J=5.9 Hz), 3.57-3.77 (4H, m),4.46-4.48 (1H, m), 5.16 (1H, d, J=19.2 Hz), 5.25 (1H, d, J=18.8 Hz),5.42 (2H, s), 5.55-5.60 (1H, m), 6.53 (1H, s), 7.00 (1H, t, J=6.3 Hz),7.17-7.26 (5H, m), 7.31 (1H, s), 7.71 (1H, t, J=5.7 Hz), 7.80 (1H, d,J=11.0 Hz), 7.92 (1H, t, J=5.7 Hz), 8.15 (1H, d, J=8.2 Hz), 8.27 (1H, t,J=5.5 Hz), 8.46 (1H, d, J=8.2 Hz).

MS (APCI) m/z: 939 (M+H)⁺

Process 2:Glycylglycyl-L-phenylalanyl-N-(4-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-4-oxobutyl)glycinamidetrifluoroacetate

The compound (72.6 mg, 77.3 μmol) obtained in Process 1 above wasreacted in the same manner as Process 2 of Example 1 to yield the titledcompound as a yellow solid (64.8 g, quantitative).

¹H-NMR (400 MHz, DMSO-d6) δ: 0.87 (3H, t, J=7.4 Hz), 1.71-1.73 (2H, m),1.82-1.90 (2H, m), 2.12-2.20 (4H, m), 2.40 (3H, s), 2.75 (1H, dd,J=13.7, 9.4 Hz), 3.03-3.09 (3H, m), 3.18-3.19 (2H, m), 3.58-3.60 (2H,m), 3.64 (1H, d, J=5.9 Hz), 3.69 (1H, d, J=5.9 Hz), 3.72 (1H, d, J=5.5Hz), 3.87 (1H, dd, J=16.8, 5.9 Hz), 4.50-4.56 (1H, m), 5.16 (1H, d,J=19.2 Hz), 5.25 (1H, d, J=18.8 Hz), 5.42 (2H, s), 5.55-5.60 (1H, m),7.17-7.27 (5H, m), 7.32 (1H, s), 7.78-7.81 (2H, m), 7.95-7.97 (3H, m),8.33-8.35 (2H, m), 8.48-8.51 (2H, m).

MS (APCI) m/z: 839 (M+H)⁺

Process 3:tert-Butyl(3S,12S)-12-benzyl-21-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-3-{[(9H-fluoren-9-ylmethoxy)carbonyl]amino}-4,7,10,13,16,21-hexaoxo-5,8,11,14,17-pentaazaheneicosan-1-noate

(2S)-4-tert-Butoxy-2-{[(9H-fluoren-9-ylmethoxy)carbonyl]amino}-4-oxobutanoicacid (0.625 g, 1.52 mmol) was dissolved in dichloromethane (10.0 mL),charged with N-hydroxysuccinimide (0.175 g, 1.52 mol) and1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (0.291 g,1.52 mmol), and stirred for 1 hour. The reaction solution was addeddropwise to an N,N′-dimethylformamide solution (10.0 mL) charged withthe compound (1.00 g, 1.01 mmol) obtained in Process 2 above, andstirred at room temperature for 20 hours. The solvent was removed underreduced pressure and the obtained residue was purified by silica gelcolumn chromatography [chloroform to chloroform:methanol=8:2 (v/v)] toyield the titled compound as a pale yellow solid (0.873 g, 70%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.88 (3H, t, J=7.4 Hz), 1.37 (9H, s),1.68-1.78 (2H, m), 1.81-1.93 (2H, m), 2.10-2.23 (4H, m), 2.41 (3H, s),2.68-2.85 (3H, m), 2.99-3.22 (5H, m), 3.58-3.81 (6H, m), 4.19-4.36 (3H,m), 4.38-4.52 (2H, m), 5.17 (1H, d, J=19.2 Hz), 5.25 (1H, d, J=19.2 Hz),5.43 (2H, s), 5.54-5.62 (1H, m), 6.55 (1H, s), 7.15-7.34 (8H, m), 7.41(2H, t, J=7.2 Hz), 7.66-7.75 (4H, m), 7.81 (1H, d, J=11.0 Hz), 7.88 (2H,d, J=7.4 Hz), 8.01-8.06 (1H, m), 8.14 (1H, d, J=8.2 Hz), 8.17-8.22 (1H,m), 8.25-8.30 (1H, m), 8.47 (1H, d, J=8.6 Hz).

MS (APCI) m/z: 1232 (M+H)⁺

Process 4:tert-Butyl(3S,12S)-12-benzyl-3-{[6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanoyl]amino}-21-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-4,7,10,13,16,21-hexaoxo-5,8,11,14,17-pentaazaheneicosan-1-noate

The compound (0.800 g, 0.649 mmol) obtained in Process 3 above wasdissolved in N,N′-dimethylformamide (3.00 mL), charged with piperidine(0.643 mL, 6.49 mmol), and stirred for 1 hour. The solvent was removedby drying under reduced pressure, and the obtained residue was dissolvedin N,N′-dimethylformamide (10 mL). N-Succinimidyl 6-maleimide hexanoate(0.300 g, 0.974 mmol) was added thereto and stirred for 20 hours. Thesolvent was removed under reduced pressure and the obtained residueswere purified by silica gel column chromatography [chloroform tochloroform:methanol=8:2 (v/v)] to yield the titled compound as a paleyellow solid (0.224 g, 29%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.87 (3H, t, J=7.6 Hz), 1.15-1.22 (2H, m),1.35 (9H, s), 1.44-1.47 (4H, m), 1.71-1.73 (2H, m), 1.80-1.91 (2H, m),2.08 (2H, t, J=7.6 Hz), 2.13-2.20 (4H, m), 2.40 (3H, s), 2.67 (1H, dt,J=11.1, 4.8 Hz), 2.78 (1H, dd, J=13.6, 9.4 Hz), 2.99-3.17 (6H, m),3.31-3.36 (2H, m), 3.57-3.76 (6H, m), 4.45-4.47 (1H, m), 4.57-4.60 (1H,m), 5.16 (1H, d, J=18.7 Hz), 5.25 (1H, d, J=18.7 Hz), 5.42 (2H, s),5.55-5.60 (1H, m), 6.53 (1H, s), 6.99 (2H, s), 7.15-7.27 (5H, m), 7.31(1H, s), 7.70 (1H, t, J=5.4 Hz), 7.80 (1H, d, J=10.9 Hz), 7.99 (1H, t,J=5.7 Hz), 8.09-8.12 (3H, m), 8.25 (1H, t, J=6.0 Hz), 8.45 (1H, d, J=9.1Hz).

MS (APCI) m/z: 1203 (M+H)⁺

Process 5:N-[6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanoyl]-L-α-aspartylglycylglycyl-L-phenylalanyl-N-(4-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-4-oxobutyl)glycinamide

The compound (0.224 g, 0.186 mmol) obtained in Process 4 above wasreacted in the same manner as Process 2 of Example 1 to yield the titledcompound as a pale yellow solid (21.2 mg, 10%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.87 (3H, t, J=7.2 Hz), 1.13-1.21 (2H, m),1.42-1.45 (6H, m), 1.70-1.72 (2H, m), 1.85-1.88 (2H, m), 2.06-2.20 (6H,m), 2.39 (3H, s), 2.63-2.67 (1H, m), 2.78-2.81 (1H, m), 3.04-3.12 (6H,m), 3.63-3.70 (6H, m), 4.46-4.52 (2H, m), 5.16 (1H, d, J=18.8 Hz), 5.25(1H, d, J=18.8 Hz), 5.42 (2H, s), 5.55-5.58 (1H, m), 6.53 (1H, s), 6.99(2H, s), 7.18-7.23 (6H, m), 7.30 (1H, s), 7.71 (1H, t, J=5.5 Hz), 7.79(1H, d, J=10.9 Hz), 7.99-8.02 (1H, m), 8.10-8.11 (3H, m), 8.27-8.30 (1H,m), 8.47-8.50 (1H, m).

MS (APCI) m/z: 1147 (M+H)⁺

Process 6: Antibody-Drug Conjugate (1)

Reduction of the antibody: The M30-H1-L4P antibody produced in ReferenceExample 2 was prepared to have antibody concentration of 10 mg/mL withPBS6.0/EDTA by using the Common procedure B (as absorption coefficientat 280 nm, 1.61 mLmg⁻¹ cm⁻¹ was used) and Common procedure C-1 describedin Production method 1. The solution (8.0 mL) was collected into a 15 mLtube and charged with an aqueous solution of 10 mM TCEP (Tokyo ChemicalIndustry Co., Ltd.) (0.124 mL; 2.3 equivalents per antibody molecule)and an aqueous solution of 1 M dipotassium hydrogen phosphate (NacalaiTesque, Inc.; 0.400 mL). After confirming that the solution had pH of7.4±0.1, the disulfide bond at hinge part in the antibody was reduced byincubating at 37° C. for 1 hour.

Conjugation between antibody and drug linker: After incubating the abovesolution at 22° C. for 10 minutes, a dimethyl sulfoxide solution (0.249mL; 4.6 equivalents per antibody molecule) containing 10 mM of thecompound obtained in Process 5 above was added thereto and incubated at22° C. for 40 minutes for conjugating the drug linker to the antibody.Next, an aqueous solution (0.050 mL; 9.2 equivalents per antibodymolecule) of 100 mM NAC (Sigma-Aldrich Co. LLC) was added thereto andincubated at 22° C. for another 20 minutes to terminate the reaction ofdrug linker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (ABS was used as buffer solution) described inProduction method 1 to yield 18.5 mL of a solution containing the titledantibody-drug conjugate.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=235300 (estimated calculation value), ε_(A,370)=0 (estimatedcalculation value), ε_(D,280)=5000 (measured average value), andε_(D,370)=19000 (measured average value) were used), the followingcharacteristic values were obtained.

Antibody concentration: 3.56 mg/mL, antibody yield: 66 mg (83%), andaverage number of conjugated drug molecules (n) per antibody molecule:3.3.

Example 3 Antibody-Drug Conjugate (2)

Process 1: Antibody-Drug Conjugate (2)

Reduction of the antibody: The M30-H1-L4P antibody produced in ReferenceExample 2 was prepared to have antibody concentration of 10 mg/mL withPBS6.0/EDTA by using the Common procedure B (as absorption coefficientat 280 nm, 1.61 mLmg⁻¹ cm⁻¹ was used) and Common procedure C-1 describedin Production method 1. The solution (8.0 mL) was collected into a 15 mLtube and charged with an aqueous solution of 10 mM TCEP (Tokyo ChemicalIndustry Co., Ltd.) (0.187 mL; 3.5 equivalents per antibody molecule)and an aqueous solution of 1 M dipotassium hydrogen phosphate (NacalaiTesque, Inc.; 0.400 mL). After confirming that the solution had pH of7.4±0.1, the disulfide bond at hinge part in the antibody was reduced byincubating at 37° C. for 1 hour.

Conjugation between antibody and drug linker: After incubating the abovesolution at 22° C. for 10 minutes, a dimethyl sulfoxide solution (0.373mL; 6.9 equivalents per antibody molecule) containing 10 mM of thecompound obtained in Process 5 of Example 2 was added thereto andincubated at 22° C. for 40 minutes for conjugating the drug linker tothe antibody. Next, an aqueous solution (0.075 mL; 13.8 equivalents perantibody molecule) of 100 mM NAC (Sigma-Aldrich Co. LLC) was addedthereto and incubated at 22° C. for another 20 minutes to terminate thereaction of drug linker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (ABS was used as buffer solution) described inProduction method 1 to yield 16 mL of a solution containing the titledantibody-drug conjugate.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=235300 (estimated calculation value), ε_(A,370)=0 (estimatedcalculation value), ε_(D,280)=5000 (measured average value), andε_(D,370)=19000 (measured average value) were used), the followingcharacteristic values were obtained.

Antibody concentration: 3.55 mg/mL, antibody yield: 57 mg (71%), andaverage number of conjugated drug molecules (n) per antibody molecule:5.5.

Example 4 Antibody-Drug Conjugate (3)

Process 1: Antibody-Drug Conjugate (3)

Reduction of the antibody: The M30-H1-L4P antibody produced in ReferenceExample 2 was prepared to have antibody concentration of 10 mg/mL byreplacing the medium with PBS6.0/EDTA by using the Common procedure C-1and Common procedure B (as absorption coefficient at 280 nm, 1.61 mLmg⁻¹cm⁻¹ was used) described in Production method 1. The solution (1.25 mL)was added to a 1.5 mL polypropylene tube and charged with an aqueoussolution of 10 mM TCEP (Tokyo Chemical Industry Co., Ltd.) (0.025 mL;3.0 equivalents per antibody molecule) and an aqueous solution of 1 Mdipotassium hydrogen phosphate (Nacalai Tesque, Inc.; 0.0625 mL). Afterconfirming that the solution had pH of 7.4±0.1, the disulfide bond athinge part in the antibody was reduced by incubating at 37° C. for 1hour.

Conjugation between antibody and drug linker: After adding dimethylsulfoxide (Sigma-Aldrich Co. LLC; 0.109 mL) and a dimethyl sulfoxidesolution containing 10 mM (0.039 mL; 4.6 equivalents per antibodymolecule) of the compound obtained in Process 5 of Example 2 to theabove solution at room temperature, it was stirred by using a tuberotator (MTR-103, manufactured by AS ONE Corporation) at roomtemperature for 40 minutes for conjugating the drug linker to theantibody. Next, an aqueous solution (0.008 mL) of 100 mM NAC(Sigma-Aldrich Co. LLC) was added thereto and stirred at roomtemperature for another 20 minutes to terminate the reaction of druglinker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (ABS was used as buffer solution) described inProduction method 1 to yield 6 mL of a solution containing the titledantibody-drug conjugate. After that, the solution was concentrated bythe Common procedure A.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=235300 (estimated calculation value), ε_(A,370)=0 (estimatedcalculation value), ε_(D,280)=5000 (measured average value), andε_(D,370)=19000 (measured average value) were used), the followingcharacteristic values were obtained.

Antibody concentration: 10.63 mg/mL, antibody yield: 7.4 mg (59%), andaverage number of conjugated drug molecules (n) per antibody molecule:3.4.

Example 5 Antibody-Drug Conjugate (4)

Process 1: Antibody-Drug Conjugate (4)

Reduction of the antibody: The M30-H1-L4P antibody produced in ReferenceExample 2 was prepared to have antibody concentration of 10 mg/mL byreplacing the medium with PBS6.0/EDTA by using the Common procedure C-1and Common procedure B (as absorption coefficient at 280 nm, 1.61 mLmg⁻¹cm⁻¹ was used) described in Production method 1. The solution (1.25 mL)was added to a 1.5 mL polypropylene tube and charged with an aqueoussolution of 10 mM TCEP (Tokyo Chemical Industry Co., Ltd.) (0.051 mL;6.0 equivalents per antibody molecule) and an aqueous solution of 1 Mdipotassium hydrogen phosphate (Nacalai Tesque, Inc.; 0.0625 mL). Afterconfirming that the solution had pH of 7.4±0.1, the disulfide bond athinge part in the antibody was reduced by incubating at 37° C. for 1hour.

Conjugation between antibody and drug linker: After adding dimethylsulfoxide (Sigma-Aldrich Co. LLC; 0.067 mL) and a dimethyl sulfoxidesolution containing 10 mM of the compound obtained in Process 5 ofExample 2 (0.085 mL; 10.0 equivalents per antibody molecule) to theabove solution at room temperature, it was stirred by using a tuberotator (MTR-103, manufactured by AS ONE Corporation) at roomtemperature for 60 minutes for conjugating the drug linker to theantibody. Next, an aqueous solution (0.013 mL) of 100 mM NAC(Sigma-Aldrich Co. LLC) was added thereto and stirred at roomtemperature for another 20 minutes to terminate the reaction of druglinker.

Purification: The above solution was subjected to purification using theCommon procedure D (ABS was used as buffer solution) described inProduction method 1 to yield 6 mL of a solution containing the titledantibody-drug conjugate.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=235300 (estimated calculation value), ε_(A,370)=0 (estimatedcalculation value), ε_(D,280)=5000 (measured average value), andε_(D,370)=19000 (measured average value) were used), the followingcharacteristic values were obtained.

Antibody concentration: 1.48 mg/mL, antibody yield: 8.88 mg (71%), andaverage number of conjugated drug molecules (n) per antibody molecule:5.8.

Example 6 Antibody-Drug Conjugate (5)

Process 1: Antibody-Drug Conjugate (5)

Reduction of the antibody: The M30-H1-L4P antibody produced in ReferenceExample 2 was prepared to have antibody concentration of 10 mg/mL byreplacing the medium with PBS6.0/EDTA by using the Common procedure C-1and Common procedure B (as absorption coefficient at 280 nm, 1.61 mLmg⁻¹cm⁻¹ was used) described in Production method 1. The solution (1.25 mL)was added to a 1.5 mL polypropylene tube and charged with an aqueoussolution of 10 mM TCEP (Tokyo Chemical Industry Co., Ltd.) (0.051 mL;6.0 equivalents per antibody molecule) and an aqueous solution of 1 Mdipotassium hydrogen phosphate (Nacalai Tesque, Inc.; 0.0625 mL). Afterconfirming that the solution had pH of 7.4±0.1, the disulfide bond athinge part in the antibody was reduced by incubating at 37° C. for 1hour.

Conjugation between antibody and drug linker: After adding dimethylsulfoxide (Sigma-Aldrich Co. LLC; 0.025 mL) and a dimethyl sulfoxidesolution containing 10 mM of the compound obtained in Process 5 ofExample 2 (0.127 mL; 15.0 equivalents per antibody molecule) to theabove solution at room temperature, it was stirred by using a tuberotator (MTR-103, manufactured by AS ONE Corporation) at roomtemperature for 60 minutes for conjugating the drug linker to theantibody. Next, an aqueous solution (0.019 mL) of 100 mM NAC(Sigma-Aldrich Co. LLC) was added thereto and stirred at roomtemperature for another 20 minutes to terminate the reaction of druglinker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (ABS was used as buffer solution) described inProduction method 1 to yield 6 mL of a solution containing the titledantibody-drug conjugate. After that, the solution was concentrated bythe Common procedure A.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=235300 (estimated calculation value), ε_(A,370)=0 (estimatedcalculation value), ε_(D,280)=5000 (measured average value), andε_(D,370)=19000 (measured average value) were used), the followingcharacteristic values were obtained.

Antibody concentration: 0.99 mg/mL, antibody yield: 5.94 mg (48%), andaverage number of conjugated drug molecules (n) per antibody molecule:6.9.

Example 7 Antibody-Drug Conjugate (6)

Almost the whole amounts of the antibody-drug conjugates of Examples 5and 6 were mixed and the solution was concentrated by the Commonprocedure A to yield the titled antibody-drug conjugate.

Antibody concentration: 10.0 mg/mL, antibody yield: 14.36 mg, andaverage number of conjugated drug molecules (n) per antibody molecule:6.2.

Example 8 Antibody-Drug Conjugate (7)

Process 1: Antibody-Drug Conjugate (7)

Reduction of the antibody: The anti-CD30 antibody produced in ReferenceExample 3 was prepared to have antibody concentration of 10 mg/mL withPBS6.0/EDTA by using the Common procedure B (as absorption coefficientat 280 nm, 1.75 mLmg⁻¹ cm⁻¹ was used) and Common procedure C-1 describedin Production method 1. The solution (1.0 mL) was collected into a 2 mLtube and charged with an aqueous solution of 10 mM TCEP (Tokyo ChemicalIndustry Co., Ltd.) (0.0148 mL; 2.3 equivalents per antibody molecule)and an aqueous solution of 1 M dipotassium hydrogen phosphate (NacalaiTesque, Inc.; 0.050 mL). After confirming that the solution had pH of7.4±0.1, the disulfide bond at hinge part in the antibody was reduced byincubating at 37° C. for 1 hour.

Conjugation between antibody and drug linker: After incubating the abovesolution at 22° C. for 10 minutes, a dimethyl sulfoxide solution (0.0297mL; 4.6 equivalents per antibody molecule) containing 10 mM of thecompound obtained in Process 5 of Example 2 was added thereto andincubated at 22° C. for 40 minutes for conjugating the drug linker tothe antibody. Next, an aqueous solution (0.00593 mL; 9.2 equivalents perantibody molecule) of 100 mM NAC (Sigma-Aldrich Co. LLC) was addedthereto and incubated at 22° C. for another 20 minutes to terminate thereaction of drug linker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (ABS was used as buffer solution) described inProduction method 1 to yield 6 mL of a solution containing the titledantibody-drug conjugate.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=270400 (estimated calculation value), ε_(A,370)=0 (estimatedcalculation value), ε_(D,280)=5000 (measured average value), andε_(D,370)=19000 (measured average value) were used), the followingcharacteristic values were obtained.

Antibody concentration: 1.18 mg/mL, antibody yield: 7.08 mg (71%), andaverage number of conjugated drug molecules (n) per antibody molecule:4.6.

Example 9 Antibody-Drug Conjugate (8)

Process 1: Antibody-Drug Conjugate (8)

Reduction of the antibody: The anti-CD30 antibody produced in ReferenceExample 3 was prepared to have antibody concentration of 10 mg/mL withPBS6.0/EDTA by using the Common procedure B (as absorption coefficientat 280 nm, 1.75 mLmg⁻¹ cm⁻¹ was used) and Common procedure C-1 describedin Production method 1. The solution (1.0 mL) was collected into a 2 mLtube and charged with an aqueous solution of 10 mM TCEP (Tokyo ChemicalIndustry Co., Ltd.) (0.0297 mL; 4.6 equivalents per antibody molecule)and an aqueous solution of 1 M dipotassium hydrogen phosphate (NacalaiTesque, Inc.; 0.050 mL). After confirming that the solution had pH of7.4±0.1, the disulfide bond at hinge part in the antibody was reduced byincubating at 37° C. for 1 hour.

Conjugation between antibody and drug linker: After incubating the abovesolution at 22° C. for 10 minutes, a dimethyl sulfoxide solution (0.0593mL; 9.2 equivalents per antibody molecule) containing 10 mM of thecompound obtained in Process 5 of Example 2 was added thereto andincubated at 22° C. for 40 minutes for conjugating the drug linker tothe antibody. Next, an aqueous solution (0.0119 mL; 18.4 equivalents perantibody molecule) of 100 mM NAC (Sigma-Aldrich Co. LLC) was addedthereto and incubated at 22° C. for another 20 minutes to terminate thereaction of drug linker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (ABS was used as buffer solution) described inProduction method 1 to yield 6 mL of a solution containing the titledantibody-drug conjugate.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=270400 (estimated calculation value), ε_(A,370)=0 (estimatedcalculation value), ε_(D,280)=5000 (measured average value), andε_(D,370)=19000 (measured average value) were used), the followingcharacteristic values were obtained.

Antibody concentration: 1.07 mg/mL, antibody yield: 6.42 mg (64%), andaverage number of conjugated drug molecules (n) per antibody molecule:7.9.

Example 10 Antibody-Drug Conjugate (9)

Process 1: Antibody-Drug Conjugate (9)

Reduction of the antibody: The anti-CD33 antibody produced in ReferenceExample 4 was prepared to have antibody concentration of 10 mg/mL withPBS6.0/EDTA by using the Common procedure B (as absorption coefficientat 280 nm, 1.66 mLmg⁻¹ cm⁻¹ was used) and Common procedure C-1 describedin Production method 1. The solution (1.0 mL) was collected into a 2 mLtube and charged with an aqueous solution of 10 mM TCEP (Tokyo ChemicalIndustry Co., Ltd.) (0.0148 mL; 2.3 equivalents per antibody molecule)and an aqueous solution of 1 M dipotassium hydrogen phosphate (NacalaiTesque, Inc.; 0.050 mL). After confirming that the solution had pH of7.4±0.1, the disulfide bond at hinge part in the antibody was reduced byincubating at 37° C. for 1 hour.

Conjugation between antibody and drug linker: After incubating the abovesolution at 22° C. for 10 minutes, a dimethyl sulfoxide solution (0.0297mL; 4.6 equivalents per antibody molecule) containing 10 mM of thecompound obtained in Process 5 of Example 2 was added thereto andincubated at 22° C. for 40 minutes for conjugating the drug linker tothe antibody. Next, an aqueous solution (0.00593 mL; 9.2 equivalents perantibody molecule) of 100 mM NAC (Sigma-Aldrich Co. LLC) was addedthereto and incubated at 22° C. for another 20 minutes to terminate thereaction of drug linker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (ABS was used as buffer solution) described inProduction method 1 to yield 6 mL of a solution containing the titledantibody-drug conjugate.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=256400 (estimated calculation value), ε_(A,370)=0 (estimatedcalculation value), ε_(D,280)=5000 (measured average value), andε_(D,370)=19000 (measured average value) were used), the followingcharacteristic values were obtained.

Antibody concentration: 1.09 mg/mL, antibody yield: 6.54 mg (65%), andaverage number of conjugated drug molecules (n) per antibody molecule:4.4.

Example 11 Antibody-Drug Conjugate (10)

Process 1: Antibody-Drug Conjugate (10)

Reduction of the antibody: The anti-CD33 antibody produced in ReferenceExample 4 was prepared to have antibody concentration of 10 mg/mL withPBS6.0/EDTA by using the Common procedure B (as absorption coefficientat 280 nm, 1.66 mLmg⁻¹ cm⁻¹ was used) and Common procedure C-1 describedin Production method 1. The solution (1.0 mL) was collected into a 2 mLtube and charged with an aqueous solution of 10 mM TCEP (Tokyo ChemicalIndustry Co., Ltd.) (0.0297 mL; 4.6 equivalents per antibody molecule)and an aqueous solution of 1 M dipotassium hydrogen phosphate (NacalaiTesque, Inc.; 0.050 mL). After confirming that the solution had pH of7.4±0.1, the disulfide bond at hinge part in the antibody was reduced byincubating at 37° C. for 1 hour.

Conjugation between antibody and drug linker: After incubating the abovesolution at 22° C. for 10 minutes, a dimethyl sulfoxide solution (0.0593mL; 9.2 equivalents per antibody molecule) containing 10 mM of thecompound obtained in Process 5 of Example 2 was added thereto andincubated at 22° C. for 40 minutes for conjugating the drug linker tothe antibody. Next, an aqueous solution (0.0119 mL; 18.4 equivalents perantibody molecule) of 100 mM NAC (Sigma-Aldrich Co. LLC) was addedthereto and incubated at 22° C. for another 20 minutes to terminate thereaction of drug linker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (ABS was used as buffer solution) described inProduction method 1 to yield 6 mL of a solution containing the titledantibody-drug conjugate.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=256400 (estimated calculation value), ε_(A,370)=0 (estimatedcalculation value), ε_(D,280)=5000 (measured average value), andε_(D,370)=19000 (measured average value) were used), the followingcharacteristic values were obtained.

Antibody concentration: 1.04 mg/mL, antibody yield: 6.24 mg (62%), andaverage number of conjugated drug molecules (n) per antibody molecule:6.6.

Example 12 Antibody-Drug Conjugate (11)

Process 1: Antibody-Drug Conjugate (11)

Reduction of the antibody: The anti-CD70 antibody produced in ReferenceExample 5 was prepared to have antibody concentration of 10 mg/mL withPBS6.0/EDTA by using the Common procedure B (as absorption coefficientat 280 nm, 1.66 mLmg⁻¹ cm⁻¹ was used) and Common procedure C-1 describedin Production method 1. The solution (1.0 mL) was collected into a 2 mLtube and charged with an aqueous solution of 10 mM TCEP (Tokyo ChemicalIndustry Co., Ltd.) (0.0148 mL; 2.3 equivalents per antibody molecule)and an aqueous solution of 1 M dipotassium hydrogen phosphate (NacalaiTesque, Inc.; 0.050 mL). After confirming that the solution had pH of7.4±0.1, the disulfide bond at hinge part in the antibody was reduced byincubating at 37° C. for 1 hour.

Conjugation between antibody and drug linker: After incubating the abovesolution at 22° C. for 10 minutes, a dimethyl sulfoxide solution (0.0297mL; 4.6 equivalents per antibody molecule) containing 10 mM of thecompound obtained in Process 5 of Example 2 was added thereto andincubated at 22° C. for 40 minutes for conjugating the drug linker tothe antibody. Next, an aqueous solution (0.00593 mL; 9.2 equivalents perantibody molecule) of 100 mM NAC (Sigma-Aldrich Co. LLC) was addedthereto and incubated at 22° C. for another 20 minutes to terminate thereaction of drug linker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (ABS was used as buffer solution) described inProduction method 1 to yield 6 mL of a solution containing the titledantibody-drug conjugate.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=262400 (estimated calculation value), ε_(A,370)=0 (estimatedcalculation value), ε_(D,280)=5000 (measured average value), andε_(D,370)=19000 (measured average value) were used), the followingcharacteristic values were obtained.

Antibody concentration: 1.12 mg/mL, antibody yield: 6.72 mg (67%), andaverage number of conjugated drug molecules (n) per antibody molecule:4.5.

Example 13 Antibody-Drug Conjugate (12)

Process 1: Antibody-Drug Conjugate (12)

Reduction of the antibody: The anti-CD70 antibody produced in ReferenceExample 5 was prepared to have antibody concentration of 10 mg/mL withPBS6.0/EDTA by using the Common procedure B (as absorption coefficientat 280 nm, 1.69 mLmg⁻¹ cm⁻¹ was used) and Common procedure C-1 describedin Production method 1. The solution (1.0 mL) was collected into a 2 mLtube and charged with an aqueous solution of 10 mM TCEP (Tokyo ChemicalIndustry Co., Ltd.) (0.0297 mL; 4.6 equivalents per antibody molecule)and an aqueous solution of 1 M dipotassium hydrogen phosphate (NacalaiTesque, Inc.; 0.050 mL). After confirming that the solution had pH of7.4±0.1, the disulfide bond at hinge part in the antibody was reduced byincubating at 37° C. for 1 hour.

Conjugation between antibody and drug linker: After incubating the abovesolution at 22° C. for 10 minutes, a dimethyl sulfoxide solution (0.0593mL; 9.2 equivalents per antibody molecule) containing 10 mM of thecompound obtained in Process 7 of Example 1 was added thereto andincubated at 22° C. for 40 minutes for conjugating the drug linker tothe antibody. Next, an aqueous solution (0.0119 mL; 18.4 equivalents perantibody molecule) of 100 mM NAC (Sigma-Aldrich Co. LLC) was addedthereto and incubated at 22° C. for another 20 minutes to terminate thereaction of drug linker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (ABS was used as buffer solution) described inProduction method 1 to yield 6 mL of a solution containing the titledantibody-drug conjugate.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=262400 (estimated calculation value), ε_(A,370)=0 (estimatedcalculation value), ε_(D,280)=5000 (measured average value), andε_(D,370)=19000 (measured average value) were used), the followingcharacteristic values were obtained.

Antibody concentration: 1.03 mg/mL, antibody yield: 6.18 mg (62%), andaverage number of conjugated drug molecules (n) per antibody molecule:7.9.

Example 14 Antibody-Drug Conjugate (13)

Process 1: tert-ButylN-(2-{2-[2-(2-hydroxyethoxyl)ethoxy]ethoxy}ethyl)glycinate

To an N,N-dimethylformamide (50.0 mL) solution of2-{2-[2-(2-hydroxyethoxyl)ethoxy]ethoxy}ethyl)-methylbenzene sulfonate(Bioorg. Med. Chem. Lett., 2011, Vol. 21, p. 550; 1.75 g, 5.00 mmol) andglycine tert-butyl hydrochloride (1.26 g, 7.52 mmol),N,N-diisopropylethylamine (1.94 g, 15.0 mmol) was added and stirred at60° C. for 10 hours. Chloroform was added to the reaction solution, theorganic layer was washed with 1 N hydrochloric acid, and the obtainedorganic layer was dried over sodium sulfate and filtered. The solventwas removed under reduced pressure and the obtained residues werepurified by silica gel column chromatography [chloroform tochloroform:methanol=8:1 (v/v)] to yield the titled compound in colorlessoily substance (426 mg, 28%).

¹H-NMR (400 MHz, CDCl₃) δ: 1.47 (9H, s), 2.80 (2H, t, J=5.3 Hz), 3.32(2H, s), 3.76-3.54 (17H, m).

Process 2: tert-ButylN-[6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanoyl]-N-(2-{2-[2-(2-hydroxyethoxyl)ethoxy]ethoxy}ethyl)glycinate

The compound (426 mg, 1.39 mmol) obtained in Process 1 above was reactedin the same manner as Process 4 of Example 2 to yield the titledcompound in colorless oily substance (489 mg, 70%).

¹H-NMR (400 MHz, CDCl₃) δ: 1.28-1.36 (2H, m), 1.45 (9H, s), 1.57-1.71(4H, m), 2.39 (2H, t, J=7.3 Hz), 3.48-3.76 (3H, m), 4.02 (2H, s), 6.68(2H, s).

Process 3:N-[6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanoyl]-N-(2-{2-[2-(2-hydroxyethoxyl)ethoxy]ethoxy}ethyl)glycine

The compound (489 mg, 0.977 mmol) obtained in Process 2 above wasreacted in the same manner as Process 2 of Example 1 to yield the titledcompound as a colorless solid (211 mg, 49%).

¹H-NMR (400 MHz, CDCl₃) δ: 1.38-1.28 (2H, m), 1.73-1.55 (4H, m), 2.28(2H, t, J=7.0 Hz), 3.50-3.79 (18H, m), 4.12 (2H, s), 6.68 (2H, s).

Process 4:N-[6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanoyl]-N-(2-{2-[2-(2-hydroxyethoxyl)ethoxy]ethoxy}ethyl)glycylglycylglycyl-L-phenylalanyl-N-(4-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-4-oxobutyl)glycinamide

The compound (48.9 mg, 0.110 mmol) obtained in Process 3 above wasreacted in the same manner as Process 1 of Example 1 by using thecompound (84.0 mg, 0.100 mmol) obtained in Process 2 of Example 2instead of methanesulfonate of the compound (4) to yield the titledcompound as a pale yellow solid (54.0 mg, 43%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.87 (3H, t, J=7.2 Hz), 1.14-1.26 (2H, m),1.39-1.51 (4H, m), 1.68-1.76 (2H, m), 1.81-1.91 (2H, m), 2.08-2.23 (4H,m), 2.40 (3H, s), 2.73-2.84 (1H, m), 2.98-3.21 (5H, m), 3.25-3.79 (26H,m), 3.93 (2H, s), 4.43-4.49 (1H, m), 4.54-4.61 (1H, m), 5.21 (2H, q,J=18.6 Hz), 5.42 (2H, s), 5.54-5.60 (1H, m), 6.53 (1H, s), 7.00 (2H, s),7.14-7.27 (5H, m), 7.31 (1H, s), 7.68-7.74 (1H, m), 7.80 (1H, d, J=11.0Hz), 8.02-8.32 (4H, m), 8.46 (1H, d, J=8.6 Hz).

MS (ESI) m/z: 1265 (M+H)⁺

Process 5: Antibody-Drug Conjugate (13)

By using the M30-H1-L4P antibody produced in Reference Example 2 and thecompound obtained in Process 4 above, the titled antibody-drug conjugatewas obtained in the same manner as Process 6 of Example 2.

Antibody concentration: 13.13 mg/mL, antibody yield: 9.2 mg (74%), andaverage number of conjugated drug molecules (n) per antibody molecule:3.4.

Example 15 Antibody-Drug Conjugate (14)

Process 1:N-(tert-butoxycarbonyl)-β-alanylglycylglycyl-L-phenylalanyl-N-(4-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-4-oxobutyl)glycinamide

The compound (0.839 g, 1.00 mmol) obtained in Process 2 of Example 2 wasreacted in the same manner as Process 3 of Example 2 by usingN-(tert-butoxycarbonyl)-β-alanine instead of N-succinimidyl 6-maleimidehexanoate. The obtained crude product was used in the next processwithout purification.

Process 2:β-Alanylglycylglycyl-L-phenylalanyl-N-(4-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-4-oxobutyl)glycinamide

The crude product obtained in Process 1 was reacted in the same manneras Process 2 of Example 1 to yield the titled compound as a pale yellowsolid (0.610 g, 67%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.87 (3H, t, J=7.4 Hz), 1.67-1.77 (2H, m),1.79-1.92 (2H, m), 2.09-2.22 (4H, m), 2.40 (3H, s), 2.46-2.55 (2H, m),2.82-2.73 (1H, m), 2.95-3.13 (5H, m), 3.14-3.21 (2H, m), 3.55-3.80 (6H,m), 4.44-4.52 (1H, m), 5.20 (2H, dd, J=35.0, 19.0 Hz), 5.42 (2H, s),5.53-5.60 (1H, m), 6.54 (1H, s), 7.14-7.28 (5H, m), 7.31 (1H, s), 7.67(2H, brs), 7.72-7.78 (1H, m), 7.80 (1H, d, J=11.0 Hz), 8.10-8.17 (2H,m), 8.29 (1H, t, J=5.9 Hz), 8.42 (1H, t, J=5.7 Hz), 8.47 (1H, d, J=8.6Hz).

Process 3:(25)-5-tert-Butoxy-2-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-5-oxopentanoicacid

5-tert-Butyl L-glutamate (1.02 g, 5.00 mmol) was dissolved in asaturated aqueous solution of sodium hydrogen carbonate (20.0 mL),charged with N-methoxycarbonylmaleimide (0.775 g, 5.00 mmol) at 0° C.,and stirred at 0° C. for 30 minutes and then stirred at room temperaturefor 1 hour. The reaction solution was rendered acidic by the addition of5 N hydrochloric acid at 0° C. and then extracted with ethyl acetate.The obtained organic layer was dried over sodium sulfate and filtered.The solvent was removed under reduced pressure to yield a crude product.The obtained crude product was used in the next process withoutpurification.

Process 4:N-[(2S)-5-tert-butoxy-2-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-5-oxopentanoyl]-β-alanylglycylglycyl-L-phenylalanyl-N-(4-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-4-oxobutyl)glycinamide

The crude product (85.0 mg, 0.300 mmol) obtained in Process 3 above wasreacted in the same manner as Process 1 of Example 1 by using thecompound (182 mg, 0.200 mmol) obtained in Process 2 above instead ofmethanesulfonate of the compound (4) to yield the titled compound as apale yellow solid (102 mg, 43%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.87 (3H, t, J=7.2 Hz), 1.35 (9H, s),1.67-1.76 (2H, m), 1.81-1.90 (2H, m), 2.35-2.05 (10H, m), 2.40 (3H, s),2.75-2.83 (1H, m), 2.99-3.13 (3H, m), 3.14-3.26 (4H, m), 3.55-3.76 (6H,m), 4.36-4.50 (2H, m), 5.21 (2H, q, J=18.9 Hz), 5.42 (2H, s), 5.54-5.61(1H, m), 6.53 (1H, s), 7.03 (2H, s), 7.17-7.26 (5H, m), 7.31 (1H, s),7.68-7.73 (1H, m), 7.80 (1H, d, J=10.6 Hz), 8.00-8.05 (2H, m), 8.12 (1H,d, J=7.8 Hz), 8.16-8.20 (1H, m), 8.23-8.28 (1H, m), 8.46 (1H, d, J=8.6Hz).

Process 5:N-[(2S)-4-carboxy-2-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)butanoyl]-β-alanylglycylglycyl-L-phenylalanyl-N-(4-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-4-oxobutyl)glycinamide

The compound (102 mg, 86.8 μmol) obtained in Process 4 above was reactedin the same manner as Process 2 of Example 1 to yield the titledcompound as a pale yellow solid (76.0 mg, 78%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.87 (3H, t, J=7.4 Hz), 1.68-1.75 (2H, m),1.84-1.91 (2H, m), 2.35-2.05 (10H, m), 2.40 (3H, s), 2.74-2.83 (1H, m),2.99-3.12 (3H, m), 3.14-3.26 (4H, m), 3.55-3.77 (6H, m), 4.41-4.49 (2H,m), 5.21 (2H, dd, J=38.7, 18.8 Hz), 5.42 (2H, s), 5.54-5.61 (1H, m),6.54 (1H, s), 7.03 (2H, s), 7.15-7.27 (5H, m), 7.31 (1H, s), 7.69-7.74(1H, m), 7.80 (1H, d, J=10.9 Hz), 8.01-8.07 (2H, m), 8.12 (1H, d, J=8.2Hz), 8.19 (1H, t, J=5.5 Hz), 8.27 (1H, t, J=6.3 Hz), 8.47 (1H, d, J=8.6Hz), 12.12 (1H, s).

MS (ESI) m/z: 1119 (M+H)⁺

Process 6: Antibody-Drug Conjugate (14)

By using the M30-H1-L4P antibody produced in Reference Example 2 and thecompound obtained in Process 5 above, the titled antibody-drug conjugatewas obtained in the same manner as Process 6 of Example 2.

Antibody concentration: 12.77 mg/mL, antibody yield: 8.9 mg (71%), andaverage number of conjugated drug molecules (n) per antibody molecule:3.0.

Example 16 Antibody-Drug Conjugate (15)

Process 1:N-[(9H-fluoren-9-ylmethoxy)carbonyl]glycylglycyl-N-(4-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-4-oxobutyl)-L-phenylalaninamide

The compound (300 mg, 0.473 mmol) obtained in Process 2 of Example 1 wasreacted in the same manner as Process 1 of Example 1 by usingN-[(9H-fluoren-9-ylmethoxy)carbonyl]glycylglycyl-L-phenylalanine (thecompound described in Japanese Patent Laid-Open No. 2002-60351; 346 mg,0.691 mmol) instead of 4-(tert-butoxycarbonylamino)butanoic acid toyield the titled compound as a pale yellow solid (230 mg, 40%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.85 (3H, t, J=7.2 Hz), 1.67-1.68 (2H, m),1.81-1.84 (2H, m), 2.13 (4H, t, J=6.8 Hz), 2.39 (3H, s), 2.76 (1H, t,J=11.4 Hz), 2.96-3.08 (4H, m), 3.16-3.17 (2H, m), 3.59-3.74 (4H, m),4.22-4.28 (2H, m), 4.39-4.42 (1H, m), 5.16-5.22 (2H, m), 5.36-5.41 (2H,m), 5.56-5.59 (1H, m), 6.52 (1H, s), 7.14-7.20 (5H, m), 7.29-7.31 (3H,m), 7.38-7.41 (2H, m), 7.61 (1H, t, J=6.0 Hz), 7.69 (2H, d, J=7.4 Hz),7.79 (1H, d, J=11.0 Hz), 7.87 (2H, d, J=7.8 Hz), 7.95 (1H, s), 8.07 (2H,t, J=4.3 Hz), 8.42 (1H, d, J=8.6 Hz).

MS (APCI) m/z: 1004 (M+H)⁺

Process 2:Glycylglycyl-N-(4-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-4-oxobutyl)-L-phenylalaninamide

To an N,N-dimethylformamide (1.00 mL) solution of the compound (226 mg,0.225 mmol) obtained in Process 1, piperidine (0.223 mL, 2.25 mmol) wasadded and stirred at room temperature for 5 hours. The solvent wasremoved under reduced pressure to yield a mixture containing the titledcompound. The mixture was used for the next reaction without furtherpurification.

Process 3:tert-Butyl(3S,12S)-12-benzyl-18-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-3-{[(9H-fluoren-9-ylmethoxy)carbonyl]amino}-4,7,10,13,18-pentaoxo-5,8,11,14-tetraazaoctadecan-1-oate

The compound (0.225 mmol) obtained in Process 2 above was reacted in thesame manner as Process 1 of Example 1 by using 4-tert-butylN-[(9H-fluoren-9-ylmethoxy)carbonyl]-L-aspartate (104 mg, 0.337 mmol)instead of 4-(tert-butoxycarbonylamino)butanoic acid to yield the titledcompound as a pale yellow solid (114 mg, 43%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.86 (3H, t, J=7.2 Hz), 1.35 (9H, s),1.66-1.69 (2H, m), 1.84-1.85 (2H, m), 2.11-2.13 (4H, m), 2.39 (3H, s),2.43-2.45 (1H, m), 2.68-2.79 (2H, m), 2.94-3.16 (5H, m), 3.66 (5H, tt,J=30.5, 10.0 Hz), 4.23-4.30 (3H, m), 4.39-4.41 (1H, m), 5.15 (1H, d,J=19.2 Hz), 5.21 (1H, d, J=18.8 Hz), 5.37 (1H, d, J=17.2 Hz), 5.42 (1H,d, J=16.0 Hz), 5.53-5.57 (1H, m), 6.54 (1H, s), 7.15-7.22 (5H, m),7.26-7.34 (3H, m), 7.38-7.40 (2H, m), 7.68-7.70 (2H, m), 7.79 (1H, d,J=10.9 Hz), 7.86-7.87 (2H, m), 7.88-7.90 (1H, m), 7.96 (1H, t, J=6.3Hz), 8.03-8.07 (2H, m), 8.20 (1H, t, J=5.5 Hz), 8.43 (1H, d, J=8.6 Hz).

MS (APCI) m/z: 1175 (M+H)⁺

Process 4:tert-Butyl(3S,12S)-3-amino-12-benzyl-18-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-4,7,10,13,18-pentaoxo-5,8,11,14-tetraazaoctadecan-1-oate

The compound (110 mg, 0.0936 mmol) obtained in Process 3 above wasreacted in the same manner as Process 2 to yield a mixture containingthe titled compound. The mixture was used for the next reaction withoutfurther purification.

Process 5:tert-Butyl(3S,12S)-12-benzyl-3-{[6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanoyl]amino}-18-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-4,7,10,13,18-pentaoxo-5,8,11,14-tetraazaoctadecan-1-oate

The compound (0.0936 mmol) obtained in Process 4 above was reacted inthe same manner as Process 4 of Example 2 to yield the titled compoundas a pale yellow solid (40.2 mg, 38%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.86 (3H, t, J=7.4 Hz), 1.17-1.19 (2H, m),1.35 (9H, s), 1.44-1.47 (4H, m), 1.66-1.67 (2H, m), 1.81-1.88 (2H, m),2.06-2.13 (6H, m), 2.39-2.41 (1H, m), 2.40 (3H, s), 2.67 (1H, dd,J=16.0, 5.5 Hz), 2.76 (1H, dd, J=13.3, 9.0 Hz), 2.96 (1H, dd, J=13.5,4.9 Hz), 3.04 (2H, td, J=13.4, 6.6 Hz), 3.18 (2H, s), 3.36 (2H, d, J=7.0Hz), 3.58 (1H, dd, J=16.8, 5.5 Hz), 3.70 (3H, dt, J=21.5, 7.2 Hz),4.38-4.41 (1H, m), 4.57-4.59 (1H, m), 5.16 (1H, d, J=18.8 Hz), 5.24 (1H,d, J=19.2 Hz), 5.38 (1H, d, J=16.4 Hz), 5.43 (1H, d, J=16.0 Hz),5.57-5.58 (1H, m), 6.54 (1H, s), 6.99 (2H, s), 7.13-7.25 (5H, m), 7.31(1H, s), 7.80 (1H, d, J=10.9 Hz), 7.94-8.04 (3H, m), 8.13-8.16 (2H, m),8.43 (1H, d, J=8.6 Hz).

MS (APCI) m/z: 1146 (M+H)⁺

Process 6:N-[6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanoyl]-L-α-aspartylglycylglycyl-N-(4-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-4-oxobutyl)-L-phenylalaninamide

The compound (40.0 mg, 0.0349 mmol) obtained in Process 5 above wasreacted in the same manner as Process 2 of Example 1 to yield the titledcompound as a pale yellow solid (33.6 g, 88%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.87 (3H, q, J=7.2 Hz), 1.14-1.20 (2H, m),1.46 (4H, td, J=14.8, 7.3 Hz), 1.67 (2H, td, J=12.9, 6.3 Hz), 1.84 (2H,dq, J=25.5, 7.2 Hz), 2.11 (6H, dt, J=23.4, 7.3 Hz), 2.39 (3H, s),2.45-2.47 (1H, m), 2.69 (1H, dd, J=16.5, 5.5 Hz), 2.76 (1H, dd, J=13.7,9.3 Hz), 2.94-3.01 (1H, m), 3.05 (2H, dq, J=25.1, 6.4 Hz), 3.17-3.19(1H, m), 3.34-3.46 (4H, m), 3.59 (1H, dd, J=16.6, 5.6 Hz), 3.69 (2H, dt,J=20.1, 6.8 Hz), 4.37-4.41 (1H, m), 4.55 (1H, dd, J=13.5, 7.7 Hz), 5.16(1H, d, J=19.0 Hz), 5.22 (1H, d, J=18.6 Hz), 5.38 (1H, d, J=16.4 Hz),5.43 (1H, d, J=16.4 Hz), 5.55-5.59 (1H, m), 6.54 (1H, s), 6.99 (2H, s),7.19 (5H, dq, J=31.6, 7.9 Hz), 7.31 (1H, s), 7.79 (1H, d, J=11.0 Hz),7.99 (3H, ddd, J=25.1, 14.2, 6.2 Hz), 8.11 (1H, t, J=5.5 Hz), 8.17 (1H,d, J=7.6 Hz), 8.44 (1H, d, J=8.5 Hz), 12.32 (1H, s).

MS (APCI) m/z: 1090 (M+H)⁺

Process 7: Antibody-Drug Conjugate (15)

Reduction of the antibody: The M30-H1-L4P antibody produced in ReferenceExample 2 was prepared to have antibody concentration of 10 mg/mL byreplacing the medium with PBS6.0/EDTA by using the Common procedure C-1and Common procedure B (as absorption coefficient at 280 nm, 1.61 mLmg⁻¹cm⁻¹ was used) described in Production method 1. The solution (1.25 mL)was added to a 1.5 mL polypropylene tube and charged with an aqueoussolution of 10 mM TCEP (Tokyo Chemical Industry Co., Ltd.) (0.025 mL;3.0 equivalents per antibody molecule) and an aqueous solution of 1 Mdipotassium hydrogen phosphate (Nacalai Tesque, Inc.; 0.0625 mL). Afterconfirming that the solution had pH of 7.4±0.1, the disulfide bond athinge part in the antibody was reduced by incubating at 37° C. for 1hour.

Conjugation between antibody and drug linker: After adding dimethylsulfoxide (Sigma-Aldrich Co. LLC; 0.102 mL) and a dimethyl sulfoxidesolution containing 10 mM of the compound obtained in above Process 6(0.047 mL; 5.5 equivalents per antibody molecule) to the above solutionat room temperature, it was stirred by using a tube rotator (MTR-103,manufactured by AS ONE Corporation) at room temperature for 40 minutesfor conjugating the drug linker to the antibody. Next, an aqueoussolution (0.009 mL) of 100 mM NAC (Sigma-Aldrich Co. LLC) was addedthereto and stirred at room temperature for another 20 minutes toterminate the reaction of drug linker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (ABS was used as buffer solution) described inProduction method 1 to yield 6 mL of a solution containing the titledantibody-drug conjugate. After that, the solution was concentrated bythe Common procedure A.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=235300 (estimated calculation value), ε_(A,370)=0 (estimatedcalculation value), ε_(D,280)=5000 (measured average value), andε_(D,370)=19000 (measured average value) were used), the followingcharacteristic values were obtained.

Antibody concentration: 9.16 mg/mL, antibody yield: 6.4 mg (51%), andaverage number of conjugated drug molecules (n) per antibody molecule:3.0.

Example 17 Antibody-Drug Conjugate (16)

Process 1:N⁶-(tert-butoxycarbonyl)-N²-[(9H-fluoren-9-ylmethoxy)carbonyl]-L-lysylglycylglycyl-L-phenylalanyl-N-(4-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-4-oxobutyl)glycinamide

The compound (167 mg, 0.176 mmol) obtained in Process 2 of Example 2 wasreacted in the same manner as Process 1 of Example 1 by usingN^(ε)-(tert-butoxycarbonyl)-N^(a)-[(9H-fluoren-9-ylmethoxy)carbonyl]-L-lysine(103 mg, 0.22 mmol) instead of 4-(tert-butoxycarbonylamino)butanoicacid. The obtained crude product was used in the next process withoutpurification.

Process 2:N⁶-(tert-butoxycarbonyl)-L-lysylglycylglycyl-L-phenylalanyl-N-(4-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-4-oxobutyl)glycinamide

To an N,N-dimethylformamide (4.00 mL) solution of the crude productobtained in Process 1 above, piperidine (0.400 mL) was added and stirredat room temperature for 2 hours. The solvent was removed under reducedpressure and the obtained residues were purified by silica gel columnchromatography [chloroform to partitioned organic layer ofchloroform:methanol:water=7:3:1 (v/v/v),] to yield the titled compoundas a pale yellow solid (113 mg, 60%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.87 (3H, t, J=7.4 Hz), 1.18-1.49 (5H, m),1.36 (9H, s), 1.51-1.60 (1H, m), 1.67-1.76 (2H, m), 1.80-1.91 (2H, m),2.09-2.20 (4H, m), 2.39 (3H, s), 2.76-2.89 (3H, m), 2.99-3.22 (6H, m),3.58-3.77 (6H, m), 4.43-4.49 (1H, m), 5.20 (2H, q, J=18.5 Hz), 5.42 (2H,s), 5.55-5.60 (1H, m), 6.54 (1H, s), 6.76 (1H, t, J=5.5 Hz), 7.15-7.26(5H, m), 7.31 (1H, s), 7.69-7.74 (1H, m), 7.80 (1H, d, J=10.9 Hz), 8.08(1H, t, J=5.7 Hz), 8.14 (1H, d, J=7.8 Hz), 8.22-8.30 (2H, m), 8.47 (1H,d, J=8.6 Hz).

Process 3:N⁶-(tert-butoxycarbonyl)-N²-[6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanoyl]-L-lysylglycylglycyl-L-phenylalanyl-N-(4-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-4-oxobutyl)glycinamide

The compound (113 mg, 0.106 mmol) obtained in Process 2 above wasreacted in the same manner as Process 4 of Example 2 to yield the titledcompound as a pale yellow solid (102 mg, 61%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.87 (3H, t, J=7.2 Hz), 1.11-1.53 (11H, m),1.35 (9H, s), 1.56-1.65 (1H, m), 1.68-1.76 (2H, m), 1.81-1.92 (2H, m),2.06-2.20 (6H, m), 2.40 (3H, s), 2.74-2.90 (3H, m), 2.96-3.39 (7H, m),3.57-3.74 (6H, m), 4.14-4.21 (1H, m), 4.42-4.49 (1H, m), 5.20 (2H, q,J=18.9 Hz), 5.42 (2H, s), 5.55-5.60 (1H, m), 6.54 (1H, s), 6.72-6.78(1H, m), 7.00 (2H, s), 7.15-7.26 (5H, m), 7.31 (1H, s), 7.69-7.72 (1H,m), 7.80 (1H, d, J=10.9 Hz), 7.93 (1H, d, J=7.4 Hz), 7.99-8.04 (1H, m),8.10-8.18 (2H, m), 8.26 (1H, t, J=6.1 Hz), 8.46 (1H, d, J=8.2 Hz).

Process 4:N²-[6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanoyl]-L-lysylglycylglycyl-L-phenylalanyl-N-(4-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-4-oxobutyl)glycinamide

To a dichloromethane (4.00 mL) solution of the compound (102 mg, 80.9μmol) obtained in Process 3 above, trifluoroacetic acid (1.00 mL) wasadded and stirred at room temperature for 2 hours. The solvent wasremoved under reduced pressure and the obtained residues were purifiedby silica gel column chromatography [chloroform to partitioned organiclayer of chloroform:methanol:water=7:3:1 (v/v/v)] to yield the titledcompound as a pale yellow solid (57.0 mg, 61%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.87 (3H, t, J=7.2 Hz), 1.12-1.35 (4H, m),1.41-1.55 (7H, m), 1.61-1.77 (3H, m), 1.80-1.91 (2H, m), 2.07-2.22 (6H,m), 2.40 (3H, s), 2.84-2.71 (3H, m), 2.97-3.40 (7H, m), 3.59-3.76 (6H,m), 4.20-4.25 (1H, m), 4.45-4.50 (1H, m), 5.20 (2H, q, J=18.5 Hz), 5.42(2H, s), 5.54-5.60 (1H, m), 6.55 (1H, s), 7.01 (2H, s), 7.15-7.26 (5H,m), 7.31 (1H, s), 7.74 (1H, t, J=5.7 Hz), 7.81 (1H, d, J=10.9 Hz), 7.97(1H, d, J=7.8 Hz), 8.05 (1H, t, J=6.1 Hz), 8.13-8.18 (2H, m), 8.28 (1H,t, J=5.7 Hz), 8.47 (1H, d, J=8.6 Hz).

MS (ESI) m/z: 1160 (M+H)⁺

Process 5: Antibody-Drug Conjugate (16)

By using the M30-H1-L4P antibody produced in Reference Example 2 and thecompound obtained in Process 4 above, the titled antibody-drug conjugatewas obtained in the same manner as Process 7 of Example 16.

Antibody concentration: 19.26 mg/mL, and average number of conjugateddrug molecules (n) per antibody molecule: 3.8.

Example 18N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]-β-alaninamide

Process 1:tert-Butyl(3-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-3-oxopropyl)carbamate

Mesylate of the compound (4) (500 mg, 0.941 mmol) was reacted in thesame manner as Process 1 of Example 1 by usingN-(tert-butoxycarbonyl)-P-alanine instead of4-(tert-butoxycarbonylamino)butanoic acid to yield the titled compoundas a yellow-brown solid (616 mg, quantitative).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.87 (3H, t, J=7.2 Hz), 1.29 (9H, s), 1.86(2H, dt, J=15.1, 7.3 Hz), 2.04-2.22 (2H, m), 2.31 (2H, t, J=6.8 Hz),2.40 (3H, s), 3.10-3.26 (4H, m), 5.15 (1H, d, J=18.8 Hz), 5.26 (1H, d,J=19.2 Hz), 5.42 (2H, dd, J=18.8, 16.4 Hz), 5.57 (1H, dt, J=8.5, 4.2Hz), 6.53 (1H, s), 6.78 (1H, t, J=5.5 Hz), 7.30 (1H, s), 7.80 (1H, d,J=11.0 Hz), 8.46 (1H, d, J=8.6 Hz).

MS (ESI) m/z: 607 (M+H)⁺

Process 2:N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]-β-alaninamide

The compound obtained in Process 1 above was reacted in the same manneras Process 2 of Example 1 to yield trifluoroacetate of the titledcompound as a yellow solid (499 mg, 86%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.87 (3H, t, J=7.2 Hz), 1.86 (2H, dquin,J=14.6, 7.2, 7.2, 7.2, 7.2 Hz), 2.06-2.27 (1H, m), 2.41 (3H, s),2.46-2.57 (2H, m), 3.08 (2H, t, J=6.8 Hz), 3.14-3.24 (2H, m), 5.22 (1H,d, J=18.8 Hz), 5.29 (1H, d, J=18.8 Hz), 5.43 (2H, s), 5.58 (1H, dt,J=8.5, 4.5 Hz), 6.55 (1H, s), 7.32 (1H, s), 7.74 (3H, brs), 7.82 (1H, d,J=11.0 Hz), 8.67 (1H, d, J=8.6 Hz).

MS (ESI) m/z: 507 (M+H)⁺

Example 19 Antibody-Drug Conjugate (17)

Process 1:N-(tert-butoxycarbonyl)glycylglycyl-L-phenylalanylglycyl-N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]-β-alaninamide

The compound (484 mg, 0.780 mmol) of Example 18 was reacted in the samemanner as Process 1 of Example 2 to yield the titled compound as a paleyellow solid (626 mg, 87%).

¹H-NMR (400 MHz, 400 MHz, DMSO-d₆) δ: 0.87 (3H, t, J=7.4 Hz), 1.27-1.42(9H, m), 1.77-1.93 (2H, m), 2.06-2.22 (2H, m), 2.36 (2H, t, J=7.2 Hz),2.40 (3H, d, J=1.6 Hz), 2.44-2.54 (2H, m), 2.76 (1H, dd, J=14.5, 10.2Hz), 3.02 (1H, dd, J=13.9, 4.5 Hz), 3.12-3.22 (2H, m), 3.52 (6H, d,J=6.3 Hz), 4.42-4.54 (1H, m), 5.19 (1H, d, J=19.2 Hz), 5.26 (1H, d,J=18.4 Hz), 5.42 (1H, dd, J=18.4, 16.4 Hz), 5.57 (1H, dt, J=8.7, 4.4Hz), 6.53 (1H, s), 6.98 (1H, t, J=5.9 Hz), 7.14-7.28 (5H, m), 7.31 (1H,s), 7.77-7.84 (1H, m), 7.91 (1H, t, J=5.5 Hz), 8.16 (1H, d, J=7.8 Hz),8.27 (1H, t, J=5.1 Hz), 8.52 (1H, d, J=9.0 Hz).

Process 2:Glycylglycyl-L-phenylalanylglycyl-N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolidino[1,2-b]quinolin-1-yl]-β-alanineamidetrifluoroacetate

The compound (624 mg, 0.675 mmol) obtained in Process 1 above wasreacted in the same manner as Process 2 of Example 2 to yield the titledcompound as a yellow solid (626 mg, 92%).

¹H-NMR (400 MHz, 400 MHz, DMSO-d₆) δ: 0.87 (3H, t, J=7.4 Hz), 1.86 (2H,tt, J=14.5, 7.2 Hz), 2.07-2.22 (2H, m), 2.36 (2H, t, J=7.2 Hz), 2.40(3H, s), 2.44-2.54 (2H, m), 2.75 (1H, dd, J=13.7, 9.8 Hz), 3.04 (1H, dd,J=13.7, 4.3 Hz), 3.12-3.22 (2H, m), 3.58 (2H, d, J=4.7 Hz), 3.69 (3H,td, J=11.2, 5.7 Hz), 3.87 (1H, dd, J=17.0, 5.7 Hz), 4.54 (1H, m, J=17.8,4.5 Hz), 5.19 (1H, d, J=19.2 Hz), 5.26 (1H, d, J=18.8 Hz), 5.43 (2H, s),5.51-5.60 (1H, m), 6.55 (1H, s), 7.14-7.29 (5H, m), 7.32 (1H, s), 7.81(1H, d, J=10.9 Hz), 7.88 (1H, t, J=5.7 Hz), 7.97 (3H, br.s.), 8.29-8.38(2H, m), 8.50 (1H, t, J=5.7 Hz), 8.55 (1H, d, J=8.6 Hz).

MS (ESI) m/z: 825 (M+H)⁺

Process 3:tert-Butyl(95,185)-9-benzyl-1-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-18-{[(9H-fluoren-9-ylmethoxy)carbonyl]amino}-1,5,8,11,14,17-hexaoxo-4,7,10,13,16-pentaazaicosan-20-noate

The compound (150 mg, 0.182 mmol) obtained in Process 2 above wasreacted in the same manner as Process 1 of Example 2 by using(2S)-4-tert-butoxy-2-{[(9H-fluoren-9-ylmethoxy)carbonyl]amino}-4-oxobutanoicacid (90.0 mg, 0.219 mmol) instead ofN-(tert-butoxycarbonyl)glycylglycyl-L-phenylalanylglycine to yield thetitled compound as a pale yellow solid (84.0 mg, 38%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.82-0.91 (3H, m), 1.35 (9H, s), 1.85 (2H,tt, J=14.0, 7.3 Hz), 2.06-2.21 (2H, m), 2.39 (3H, s), 2.31-2.53 (5H, m),2.64-2.73 (1H, m), 2.78 (1H, dd, J=13.7, 9.8 Hz), 3.02 (1H, dd, J=13.9,4.5 Hz), 3.11-3.20 (2H, m), 3.55-3.80 (6H, m), 4.17-4.35 (3H, m),4.35-4.43 (1H, m), 4.44-4.51 (1H, m), 5.18 (1H, d, J=19.2 Hz), 5.24 (1H,d, J=19.2 Hz), 5.41 (2H, dd, J=18.8, 16.4 Hz), 5.51-5.60 (1H, m), 6.53(1H, s), 7.13-7.20 (1H, m), 7.20-7.27 (4H, m), 7.27-7.34 (3H, m), 7.39(2H, t, J=7.2 Hz), 7.65-7.73 (3H, m), 7.79 (2H, d, J=10.6 Hz), 7.87 (2H,d, J=7.4 Hz), 8.00 (1H, t, J=6.1 Hz), 8.08-8.20 (2H, m), 8.22-8.31 (1H,m), 8.52 (1H, d, J=8.2 Hz).

MS (ESI) m/z: 1218 (M+H)′

Process 4:tert-Butyl(95,185)-9-benzyl-18-{[6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanoyl]amino}-1-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-1,5,8,11,14,17-hexaoxo-4,7,10,13,16-pentaazaicosan-20-noate

The compound (81.0 mg, 0.0665 mmol) obtained in Process 3 above wasreacted in the same manner as Process 4 of Example 2 to yield the titledcompound (56.0 mg, 71%).

MS (ESI) m/z: 1189.5 (M+H)⁺

Process 5:N-[6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanoyl]-L-α-aspartylglycylglycyl-L-phenylalanylglycyl-N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]-β-alaninamide

The compound (52.0 mg, 0.0437 mmol) obtained in Process 4 above wasreacted in the same manner as Process 2 of Example 1 to yield the titledcompound as a pale yellow solid (35.0 mg, 71%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.87 (3H, t, J=7.4 Hz), 1.12-1.22 (2H, m),1.39-1.51 (4H, m), 1.78-1.92 (2H, m), 2.04-2.19 (2H, m), 2.08 (2H, t,J=7.2 Hz), 2.40 (3H, s), 2.31-2.46 (6H, m), 2.61-2.72 (1H, m), 2.73-2.85(1H, m), 3.02 (1H, dd, J=14.1, 4.7 Hz), 3.17 (2H, m, J=5.5 Hz),3.26-3.43 (2H, m), 3.55-3.77 (6H, m), 4.42-4.50 (1H, m), 4.51-4.58 (1H,m), 5.19 (1H, d, J=18.4 Hz), 5.26 (1H, d, J=18.4 Hz), 5.42 (2H, brs),5.52-5.60 (1H, m), 6.53 (1H, s), 6.99 (2H, s), 7.12-7.27 (5H, m), 7.31(1H, s), 7.80 (2H, d, J=10.9 Hz), 7.93-8.02 (1H, m), 8.03-8.17 (3H, m),8.22-8.31 (1H, m), 8.53 (1H, d, J=8.6 Hz).

MS (ESI) m/z: 1133 (M+H)⁺

Process 6: Antibody-Drug Conjugate (17)

By using the M30-H1-L4P antibody produced in Reference Example 2 and thecompound obtained in Process 5 above, the titled antibody-drug conjugatewas obtained in the same manner as Process 1 of Example 4.

Antibody concentration: 9.56 mg/mL, antibody yield: 6.7 mg (54%), andaverage number of conjugated drug molecules (n) per antibody molecule:3.5.

Example 20 Antibody-Drug Conjugate (18)

Process 1:tert-Butyl(5S,14S)-5-benzyl-1-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-14-{[(9H-fluoren-9-ylmethoxy)carbonyl]amino}-1,4,7,10,13-pentaoxo-3,6,9,12-tetraazahexadecan-16-oate

Under ice cooling, to an N,N-dimethylformamide (10.0 mL) solution ofglycylglycyl-L-phenylalanyl-N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]glycinamide(a free form of the pharmaceutical compound described in WO97/46260;0.250 g, 0.332 mmol), N-hydroxysuccinimide (57.2 mg, 0.497 mmol), and4-tert-butyl N-[(9H-fluoren-9-ylmethoxy)carbonyl]-L-aspartate (0.205 g,0.497 mmol), N,N′-dicyclohexylcarbodiimide (0.123 g, 0.497 mmol) wasadded and stirred at room temperature for 2 days. The solvent wasremoved under reduced pressure and the obtained residues were purifiedby silica gel column chromatography [chloroform tochloroform:methanol=9:1 (v/v)] to yield the titled compound as a paleyellow solid (0.278 g, 73%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.86 (3H, t, J=7.1 Hz), 1.35 (9H, s),1.79-1.90 (2H, m), 2.03-2.25 (2H, m), 2.40 (3H, s), 2.40-2.51 (2H, m),2.64-2.82 (2H, m), 2.98 (1H, dd, J=13.7, 4.6 Hz), 3.16 (2H, brs), 3.55(1H, dd, J=16.7, 5.7 Hz), 3.63-3.80 (4H, m), 4.16-4.34 (3H, m),4.36-4.50 (2H, m), 5.23 (2H, s), 5.37 (1H, d, J=16.5 Hz), 5.43 (1H, d,J=16.5 Hz), 5.51-5.62 (1H, m), 6.52 (1H, s), 7.10-7.25 (5H, m),7.26-7.33 (3H, m), 7.39 (2H, t, J=7.3 Hz), 7.65-7.72 (3H, m), 7.80 (1H,d, J=11.0 Hz), 7.86 (2H, d, J=7.3 Hz), 7.98 (1H, t, J=5.5 Hz), 8.07 (1H,d, J=7.8 Hz), 8.15 (1H, t, J=5.5 Hz), 8.31 (1H, t, J=5.5 Hz), 8.41 (1H,d, J=8.7 Hz).

MS (ESI) m/z: 1147 (M+H)⁺

Process 2:tert-Butyl(55,145)-14-amino-5-benzyl-1-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-1,4,7,10,13-pentaoxo-3,6,9,12-tetraazahexadecan-16-oate

To an N,N-dimethylformamide (2.00 mL) solution of the compound (0.279 g,0.242 mmol) obtained in Process 1 above, piperidine (0.240 mL, 2.42mmol) was added and stirred at room temperature for 1 hour. The solventwas removed under reduced pressure and the obtained residues werepurified by silica gel column chromatography [chloroform tochloroform:methanol=2:1 (v/v)] to yield the titled compound as a paleyellow solid (0.265 g, quantitative).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.88 (3H, t, J=7.2 Hz), 1.39 (9H, s),1.81-1.94 (1H, m), 2.07-2.28 (2H, m), 2.37 (1H, dd, J=15.8, 8.0 Hz),2.43 (3H, s), 2.60 (1H, dd, J=15.8, 4.9 Hz), 2.75-2.82 (1H, m), 3.00(1H, dd, J=13.9, 4.5 Hz), 3.16-3.25 (2H, m), 3.50-3.61 (2H, m),3.65-3.81 (5H, m), 4.40-4.51 (1H, m), 5.27 (2H, dd, J=24.1, 19.0 Hz),5.43 (2H, dd, J=21.3, 16.2 Hz), 5.56-5.65 (1H, m), 6.55 (1H, s),7.15-7.28 (5H, m), 7.33 (1H, s), 7.83 (1H, d, J=11.0 Hz), 8.04 (1H, t,J=5.7 Hz), 8.09 (1H, d, J=8.2 Hz), 8.26-8.39 (2H, m), 8.44 (1H, d, J=8.2Hz).

Process 3:tert-Butyl(5S,14S)-5-benzyl-14-{[6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanoyl]amino}-1-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-1,4,7,10,13-pentaoxo-3,6,9,12-tetraazahexadecan-16-oate

To an N,N-dimethylformamide (2.00 mL) solution of the compound (0.100 g,0.108 mmol) obtained in Process 2 above, N-succinimidyl 6-maleimidehexanoate (40.0 mg, 0.130 mmol) was added and stirred at roomtemperature for 2 days. The solvent was removed under reduced pressureand the obtained residues were purified by silica gel columnchromatography [chloroform to chloroform: methanol=9:1 (v/v)] to yieldthe titled compound as a pale yellow solid (80.0 mg, 66%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.88 (3H, t, J=7.2 Hz), 1.13-1.23 (2H, m),1.37 (9H, s), 1.42-1.54 (4H, m), 1.80-1.96 (2H, m), 2.08-2.25 (4H, m),2.35-3.76 (15H, m), 2.43 (3H, s), 4.39-4.49 (1H, m), 4.55-4.67 (1H, m),5.21-5.34 (2H, m), 5.43 (2H, dd, J=21.1, 16.4 Hz), 5.56-5.64 (1H, m),6.55 (1H, s), 7.01 (2H, d, J=0.8 Hz), 7.16-7.26 (5H, m), 7.33 (1H, s),7.83 (1H, d, J=11.3 Hz), 8.04-8.18 (3H, m), 8.30-8.37 (1H, m), 8.43 (1H,d, J=8.6 Hz).

MS (ESI) m/z: 1118 (M+H)⁺

Process 4:N-[6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanoyl]-L-α-aspartylglycylglycyl-L-phenylalanyl-N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]glycinamide

Under ice cooling, to the compound (70.0 mg, 62.6 μmol) obtained inProcess 3 above, trifluoroacetic acid (4.00 mL) was added and stirred atroom temperature for 1 hour. The solvent was removed under reducedpressure to yield the titled compound as a pale yellow solid (55.0 mg,83%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.88 (3H, t, J=7.4 Hz), 1.14-1.24 (2H, m),1.41-1.53 (4H, m), 1.79-1.95 (2H, m), 2.08-2.28 (4H, m), 2.37-2.60 (2H,m), 2.42 (3H, s), 2.63-2.82 (2H, m), 2.99 (1H, dd, J=14.1, 5.1 Hz),3.12-3.25 (2H, m), 3.29-3.44 (1H, m), 3.52-3.80 (6H, m), 4.38-4.48 (1H,m), 4.56 (1H, dd, J=13.7, 7.4 Hz), 5.27 (2H, dd, J=24.3, 18.8 Hz), 5.43(2H, dd, J=21.5, 16.4 Hz), 5.57-5.62 (1H, m), 6.55 (1H, s), 7.01 (2H,s), 7.15-7.26 (5H, m), 7.33 (1H, s), 7.82 (1H, d, J=11.0 Hz), 7.98 (1H,brs), 8.08 (1H, d, J=6.7 Hz), 8.15 (1H, d, J=7.8 Hz), 8.34 (1H, brs),8.44 (1H, d, J=8.6 Hz), 12.26 (1H, brs).

MS (ESI) m/z: 1062 (M+H)⁺

Process 5: Antibody-Drug Conjugate (18)

Reduction of the antibody: The M30-H1-L4P antibody produced in ReferenceExample 2 was prepared to have antibody concentration of 10 mg/mL withPBS6.0/EDTA by using the Common procedure B (as absorption coefficientat 280 nm, 1.61 mLmg⁻¹ cm⁻¹ was used) and Common procedure C-1 describedin Production method 1. The solution (8.0 mL) was collected into a 15 mLtube and charged with an aqueous solution of 10 mM TCEP (Tokyo ChemicalIndustry Co., Ltd.) (0.124 mL; 2.3 equivalents per antibody molecule)and an aqueous solution of 1 M dipotassium hydrogen phosphate (NacalaiTesque, Inc.; 0.400 mL). After confirming that the solution had pH of7.4±0.1, the disulfide bond at hinge part in the antibody was reduced byincubating at 37° C. for 1 hour.

Conjugation between antibody and drug linker: After incubating the abovesolution at 22° C. for 10 minutes, a dimethyl sulfoxide solution (0.249mL; 4.6 equivalents per antibody molecule) containing 10 mM of thecompound obtained in Process 4 above was added thereto and incubated at22° C. for 40 minutes for conjugating the drug linker to the antibody.Next, an aqueous solution (0.050 mL; 9.2 equivalents per antibodymolecule) of 100 mM NAC (Sigma-Aldrich Co. LLC) was added thereto andincubated at 22° C. for another 20 minutes to terminate the reaction ofdrug linker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (ABS was used as buffer solution) described inProduction method 1 to yield 17.5 mL of a solution containing the titledantibody-drug conjugate.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=235300 (estimated calculation value), ε_(A,370)=0 (estimatedcalculation value), ε_(D,280)=5000 (measured average value), andε_(D,370)=19000 (measured average value) were used), the followingcharacteristic values were obtained.

Antibody concentration: 3.56 mg/mL, antibody yield: 62 mg (77%), andaverage number of conjugated drug molecules (n) per antibody molecule:3.5.

Example 21 Antibody-Drug Conjugate (19)

Process 1: Antibody-Drug Conjugate (19)

Reduction of the antibody: The M30-H1-L4P antibody produced in ReferenceExample 2 was prepared to have antibody concentration of 10 mg/mL withPBS6.0/EDTA by using the Common procedure B (as absorption coefficientat 280 nm, 1.61 mLmg⁻¹ cm⁻¹ was used) and Common procedure C-1 describedin Production method 1. The solution (8.0 mL) was collected into a 15 mLtube and charged with an aqueous solution of 10 mM TCEP (Tokyo ChemicalIndustry Co., Ltd.) (0.187 mL; 3.5 equivalents per antibody molecule)and an aqueous solution of 1 M dipotassium hydrogen phosphate (NacalaiTesque, Inc.; 0.400 mL). After confirming that the solution had pH near7.4±0.1, the disulfide bond at hinge part in the antibody was reduced byincubating at 37° C. for 1 hour.

Conjugation between antibody and drug linker: After incubating the abovesolution at 22° C. for 10 minutes, a dimethyl sulfoxide solution (0.373mL; 6.9 equivalents per antibody molecule) containing 10 mM of thecompound obtained in Process 4 of Example 20 was added thereto andincubated at 22° C. for 40 minutes for conjugating the drug linker tothe antibody. Next, an aqueous solution (0.075 mL; 13.8 equivalents perantibody molecule) of 100 mM NAC (Sigma-Aldrich Co. LLC) was addedthereto and incubated at 22° C. for another 20 minutes to terminate thereaction of drug linker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (ABS was used as buffer solution) described inProduction method 1 to yield 16 mL of a solution containing the titledantibody-drug conjugate.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=235300 (estimated calculation value), ε_(A,370)=0 (estimatedcalculation value), ε_(D,280)=5000 (measured average value), andε_(D,370)=19000 (measured average value) were used), the followingcharacteristic values were obtained.

Antibody concentration: 3.66 mg/mL, antibody yield: 59 mg (74%), andaverage number of conjugated drug molecules (n) per antibody molecule:5.2.

Example 22 Antibody-Drug Conjugate (20)

Process 1: Antibody-Drug Conjugate (20)

Reduction of the antibody: The M30-H1-L4P antibody produced in ReferenceExample 2 was prepared to have antibody concentration of 10 mg/mL byreplacing the medium with PBS6.0/EDTA by using the Common procedure C-1and Common procedure B (as absorption coefficient at 280 nm, 1.61 mLmg⁻¹cm⁻¹ was used) described in Production method 1. The solution (1.25 mL)was added to a 1.5 mL polypropylene tube and charged with an aqueoussolution of 10 mM TCEP (Tokyo Chemical Industry Co., Ltd.) (0.025 mL;3.0 equivalents per antibody molecule) and an aqueous solution of 1 Mdipotassium hydrogen phosphate (Nacalai Tesque, Inc.; 0.0625 mL). Afterconfirming that the solution had pH of 7.4±0.1, the disulfide bond athinge part in the antibody was reduced by incubating at 37° C. for 1hour.

Conjugation between antibody and drug linker: After adding dimethylsulfoxide (Sigma-Aldrich Co. LLC; 0.109 mL) and a dimethyl sulfoxidesolution containing 10 mM of the compound obtained in Process 4 ofExample 20 (0.039 mL; 4.6 equivalents per antibody molecule) to theabove solution at room temperature, it was stirred by using a tuberotator (MTR-103, manufactured by AS ONE Corporation) at roomtemperature for 40 minutes for conjugating the drug linker to theantibody. Next, an aqueous solution of 100 mM NAC (Sigma-Aldrich Co.LLC; 0.008 mL) was added thereto and stirred at room temperature foranother 20 minutes to terminate the reaction of drug linker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (ABS was used as buffer solution) described inProduction method 1 to yield 6 mL of a solution containing the titledantibody-drug conjugate. After that, the solution was concentrated bythe Common procedure A described in Production method 1.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=235300 (estimated calculation value), ε_(A,370)=0 (estimatedcalculation value), ε_(D,280)=5000 (measured average value), andε_(D,370)=19000 (measured average value) were used), the followingcharacteristic values were obtained.

Antibody concentration: 11.14 mg/mL, antibody yield: 7.8 mg (62%), andaverage number of conjugated drug molecules (n) per antibody molecule:3.8.

Example 23 Antibody-Drug Conjugate (21)

Process 1: Antibody-Drug Conjugate (21)

Reduction of the antibody: The M30-H1-L4P antibody produced in ReferenceExample 2 was prepared to have antibody concentration of 10 mg/mL byreplacing the medium with PBS6.0/EDTA by using the Common procedure C-1and Common procedure B (as absorption coefficient at 280 nm, 1.61 mLmg⁻¹cm⁻¹ was used) described in Production method 1. The solution (1.25 mL)was added to a 1.5 mL polypropylene tube and charged with an aqueoussolution of 10 mM TCEP (Tokyo Chemical Industry Co., Ltd.) (0.051 mL;6.0 equivalents per antibody molecule) and an aqueous solution of 1 Mdipotassium hydrogen phosphate (Nacalai Tesque, Inc.; 0.0625 mL). Afterconfirming that the solution had pH of 7.4±0.1, the disulfide bond athinge part in the antibody was reduced by incubating at 37° C. for 1hour.

Conjugation between antibody and drug linker: After adding dimethylsulfoxide (Sigma-Aldrich Co. LLC; 0.067 mL) and a dimethyl sulfoxidesolution containing 10 mM of the compound obtained in Process 4 ofExample 20 (0.085 mL; 10.0 equivalents per antibody molecule) to theabove solution at room temperature, it was stirred by using a tuberotator (MTR-103, manufactured by AS ONE Corporation) at roomtemperature for 60 minutes for conjugating the drug linker to theantibody. Next, an aqueous solution (0.013 mL) of 100 mM NAC(Sigma-Aldrich Co. LLC) was added thereto and stirred at roomtemperature for another 20 minutes to terminate the reaction of druglinker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (ABS was used as buffer solution) described inProduction method 1 to yield 6 mL of a solution containing the titledantibody-drug conjugate.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=235300 (estimated calculation value), ε_(A,370)=0 (estimatedcalculation value), ε_(D,280)=5000 (measured average value), andε_(D,370)=19000 (measured average value) were used), the followingcharacteristic values were obtained.

Antibody concentration: 0.88 mg/mL, antibody yield: 5.28 mg (42%), andaverage number of conjugated drug molecules (n) per antibody molecule:6.4.

Example 24 Antibody-Drug Conjugate (22)

Process 1: Antibody-Drug Conjugate (22)

Reduction of the antibody: The M30-H1-L4P antibody produced in ReferenceExample 2 was prepared to have antibody concentration of 10 mg/mL byreplacing the medium with PBS6.0/EDTA by using the Common procedure C-1and Common procedure B (as absorption coefficient at 280 nm, 1.61 mLmg⁻¹cm⁻¹ was used) described in Production method 1. The solution (1.25 mL)was added to a 1.5 mL polypropylene tube and charged with an aqueoussolution of 10 mM TCEP (Tokyo Chemical Industry Co., Ltd.) (0.051 mL;6.0 equivalents per antibody molecule) and an aqueous solution of 1 Mdipotassium hydrogen phosphate (Nacalai Tesque, Inc.; 0.0625 mL). Afterconfirming that the solution had pH of 7.4±0.1, the disulfide bond athinge part in the antibody was reduced by incubating at 37° C. for 1hour.

Conjugation between antibody and drug linker: After adding dimethylsulfoxide (Sigma-Aldrich Co. LLC; 0.025 mL) and a dimethyl sulfoxidesolution (0.127 mL; 15.0 equivalents per antibody molecule) containing10 mM of the compound obtained in Process 4 of Example 20 to the abovesolution at room temperature, it was stirred by using a tube rotator(MTR-103, manufactured by AS ONE Corporation) at room temperature for 60minutes for conjugating the drug linker to the antibody. Next, anaqueous solution (0.019 mL) of 100 mM NAC (Sigma-Aldrich Co. LLC) wasadded thereto and stirred at room temperature for another 20 minutes toterminate the reaction of drug linker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (ABS was used as buffer solution) described inProduction method 1 to yield 6 mL of a solution containing the titledantibody-drug conjugate. After that, the solution was concentrated bythe Common procedure A described in Production method 1.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=235300 (estimated calculation value), ε_(A,370)=0 (estimatedcalculation value), ε_(D,280)=5000 (measured average value), andε_(D,370)=19000 (measured average value) were used), the followingcharacteristic values were obtained.

Antibody concentration: 1.19 mg/mL, antibody yield: 7.14 mg (57%), andaverage number of conjugated drug molecules (n) per antibody molecule:6.9.

Example 25 Antibody-Drug Conjugate (23)

Almost the whole amounts of the antibody-drug conjugates of Examples 23and 24 were mixed and the solution was concentrated by the Commonprocedure A described in Production method 1 to yield the titledantibody-drug conjugate.

Antibody concentration: 10.0 mg/mL, antibody yield: 9.07 mg, and averagenumber of conjugated drug molecules (n) per antibody molecule: 6.6.

Example 26 Antibody-Drug Conjugate (24)

Process 1: Antibody-Drug Conjugate (24)

Reduction of the antibody: The anti-CD30 antibody produced in ReferenceExample 3 was prepared to have antibody concentration of 10 mg/mL withPBS6.0/EDTA by using the Common procedure B (as absorption coefficientat 280 nm, 1.75 mLmg⁻¹ cm⁻¹ was used) and Common procedure C-1 describedin Production method 1. The solution (1.0 mL) was collected into a 2 mLtube and charged with an aqueous solution of 10 mM TCEP (Tokyo ChemicalIndustry Co., Ltd.) (0.0148 mL; 2.3 equivalents per antibody molecule)and an aqueous solution of 1 M dipotassium hydrogen phosphate (NacalaiTesque, Inc.; 0.050 mL). After confirming that the solution had pH of7.4±0.1, the disulfide bond at hinge part in the antibody was reduced byincubating at 37° C. for 1 hour.

Conjugation between antibody and drug linker: After incubating the abovesolution at 22° C. for 10 minutes, a dimethyl sulfoxide solution (0.0297mL; 4.6 equivalents per antibody molecule) containing 10 mM of thecompound obtained in Process 4 of Example 20 was added thereto andincubated at 22° C. for 40 minutes for conjugating the drug linker tothe antibody. Next, an aqueous solution (0.00593 mL; 9.2 equivalents perantibody molecule) of 100 mM NAC (Sigma-Aldrich Co. LLC) was addedthereto and incubated at 22° C. for another 20 minutes to terminate thereaction of drug linker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (ABS was used as buffer solution) described inProduction method 1 to yield 6 mL of a solution containing the titledantibody-drug conjugate.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=270400 (estimated calculation value), ε_(A,370)=0 (estimatedcalculation value), ε_(D,280)=5000 (measured average value), andε_(D,370)=19000 (measured average value) were used), the followingcharacteristic values were obtained.

Antibody concentration: 0.95 mg/mL, antibody yield: 5.70 mg (57%), andaverage number of conjugated drug molecules (n) per antibody molecule:2.9.

Example 27 Antibody-Drug Conjugate (25)

Process 1: Antibody-Drug Conjugate (25)

Reduction of the antibody: The anti-CD30 antibody produced in ReferenceExample 3 was prepared to have antibody concentration of 10 mg/mL withPBS6.0/EDTA by using the Common procedure B (as absorption coefficientat 280 nm, 1.75 mLmg⁻¹ cm⁻¹ was used) and Common procedure C-1 describedin Production method 1. The solution (1.0 mL) was collected into a 2 mLtube and charged with an aqueous solution of 10 mM TCEP (Tokyo ChemicalIndustry Co., Ltd.) (0.0297 mL; 4.6 equivalents per antibody molecule)and an aqueous solution of 1 M dipotassium hydrogen phosphate (NacalaiTesque, Inc.; 0.050 mL). After confirming that the solution had pH of7.4±0.1, the disulfide bond at hinge part in the antibody was reduced byincubating at 37° C. for 1 hour.

Conjugation between antibody and drug linker: After incubating the abovesolution at 22° C. for 10 minutes, a dimethyl sulfoxide solution (0.0593mL; 9.2 equivalents per antibody molecule) containing 10 mM of thecompound obtained in Process 4 of Example 20 was added thereto andincubated at 22° C. for 40 minutes for conjugating the drug linker tothe antibody. Next, an aqueous solution (0.0119 mL; 18.4 equivalents perantibody molecule) of 100 mM NAC (Sigma-Aldrich Co. LLC) was addedthereto and incubated at 22° C. for another 20 minutes to terminate thereaction of drug linker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (ABS was used as buffer solution) described inProduction method 1 to yield 6 mL of a solution containing the titledantibody-drug conjugate.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=270400 (estimated calculation value), ε_(A,370)=0 (estimatedcalculation value), ε_(D,280)=5000 (measured average value), andε_(D,370)=19000 (measured average value) were used), the followingcharacteristic values were obtained.

Antibody concentration: 1.04 mg/mL, antibody yield: 6.24 mg (62%), andaverage number of conjugated drug molecules (n) per antibody molecule:4.8.

Example 28 Antibody-Drug Conjugate (26)

Process 1: Antibody-Drug Conjugate (26)

Reduction of the antibody: The anti-CD33 antibody produced in ReferenceExample 4 was prepared to have antibody concentration of 10 mg/mL withPBS6.0/EDTA by using the Common procedure B (as absorption coefficientat 280 nm, 1.66 mLmg⁻¹ cm⁻¹ was used) and Common procedure C-1 describedin Production method 1. The solution (1.0 mL) was collected into a 2 mLtube and charged with an aqueous solution of 10 mM TCEP (Tokyo ChemicalIndustry Co., Ltd.) (0.0148 mL; 2.3 equivalents per antibody molecule)and an aqueous solution of 1 M dipotassium hydrogen phosphate (NacalaiTesque, Inc.; 0.050 mL). After confirming that the solution had pH of7.4±0.1, the disulfide bond at hinge part in the antibody was reduced byincubating at 37° C. for 1 hour.

Conjugation between antibody and drug linker: After incubating the abovesolution at 22° C. for 10 minutes, a dimethyl sulfoxide solution (0.0297mL; 4.6 equivalents per antibody molecule) containing 10 mM of thecompound obtained in Process 4 of Example 20 was added thereto andincubated at 22° C. for 40 minutes for conjugating the drug linker tothe antibody. Next, an aqueous solution (0.00593 mL; 9.2 equivalents perantibody molecule) of 100 mM NAC (Sigma-Aldrich Co. LLC) was addedthereto and incubated at 22° C. for another 20 minutes to terminate thereaction of drug linker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (ABS was used as buffer solution) described inProduction method 1 to yield 6 mL of a solution containing the titledantibody-drug conjugate.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=256400 (estimated calculation value), ε_(A,370)=0 (estimatedcalculation value), ε_(D,280)=5000 (measured average value), andε_(D,370)=19000 (measured average value) were used), the followingcharacteristics values were obtained.

Antibody concentration: 0.96 mg/mL, antibody yield: 5.76 mg (58%), andaverage number of conjugated drug molecules (n) per antibody molecule:3.0.

Example 29 Antibody-Drug Conjugate (27)

Process 1: Antibody-Drug Conjugate (27)

Reduction of the antibody: The anti-CD33 antibody produced in ReferenceExample 4 was prepared to have antibody concentration of 10 mg/mL withPBS6.0/EDTA by using the Common procedure B (as absorption coefficientat 280 nm, 1.66 mLmg⁻¹ cm⁻¹ was used) and Common procedure C-1 describedin Production method 1. The solution (1.0 mL) was collected into a 2 mLtube and charged with an aqueous solution of 10 mM TCEP (Tokyo ChemicalIndustry Co., Ltd.) (0.0297 mL; 4.6 equivalents per antibody molecule)and an aqueous solution of 1 M dipotassium hydrogen phosphate (NacalaiTesque, Inc.; 0.050 mL). After confirming that the solution had pH of7.4±0.1, the disulfide bond at hinge part in the antibody was reduced byincubating at 37° C. for 1 hour.

Conjugation between antibody and drug linker: After incubating the abovesolution at 22° C. for 10 minutes, a dimethyl sulfoxide solution (0.0593mL; 9.2 equivalents per antibody molecule) containing 10 mM of thecompound obtained in Process 4 of Example 20 was added thereto andincubated at 22° C. for 40 minutes for conjugating the drug linker tothe antibody. Next, an aqueous solution (0.0119 mL; 18.4 equivalents perantibody molecule) of 100 mM NAC (Sigma-Aldrich Co. LLC) was addedthereto and incubated at 22° C. for another 20 minutes to terminate thereaction of drug linker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (ABS was used as buffer solution) described inProduction method 1 to yield 6 mL of a solution containing the titledantibody-drug conjugate.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=256400 (estimated calculation value), ε_(A,370)=0 (estimatedcalculation value), ε_(D,280)=5000 (measured average value), andε_(D,370)=19000 (measured average value) were used), the followingcharacteristic values were obtained.

Antibody concentration: 0.95 mg/mL, antibody yield: 5.70 mg (57%), andaverage number of conjugated drug molecules (n) per antibody molecule:5.1.

Example 30 Antibody-Drug Conjugate (28)

Process 1: Antibody-Drug Conjugate (28)

Reduction of the antibody: The anti-CD70 antibody produced in ReferenceExample 5 was prepared to have antibody concentration of 10 mg/mL withPBS6.0/EDTA by using the Common procedure B (as absorption coefficientat 280 nm, 1.69 mLmg⁻¹ cm⁻¹ was used) and Common procedure C-1 describedin Production method 1. The solution (1.0 mL) was collected into a 2 mLtube and charged with an aqueous solution of 10 mM TCEP (Tokyo ChemicalIndustry Co., Ltd.) (0.0148 mL; 2.3 equivalents per antibody molecule)and an aqueous solution of 1 M dipotassium hydrogen phosphate (NacalaiTesque, Inc.; 0.050 mL). After confirming that the solution had pH of7.4±0.1, the disulfide bond at hinge part in the antibody was reduced byincubating at 37° C. for 1 hour.

Conjugation between antibody and drug linker: After incubating the abovesolution at 22° C. for 10 minutes, a dimethyl sulfoxide solution (0.0297mL; 4.6 equivalents per antibody molecule) containing 10 mM of thecompound obtained in Process 4 of Example 20 was added thereto andincubated at 22° C. for 40 minutes for conjugating the drug linker tothe antibody. Next, an aqueous solution (0.00593 mL; 9.2 equivalents perantibody molecule) of 100 mM NAC (Sigma-Aldrich Co. LLC) was addedthereto and incubated at 22° C. for another 20 minutes to terminate thereaction of drug linker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (ABS was used as buffer solution) described inProduction method 1 to yield 6 mL of a solution containing the titledantibody-drug conjugate.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=262400 (estimated calculation value), ε_(A,370)=0 (estimatedcalculation value), ε_(D,280)=5000 (measured average value), andε_(D,370)=19000 (measured average value) were used), the followingcharacteristics values were obtained.

Antibody concentration: 1.01 mg/mL, antibody yield: 6.06 mg (61%), andaverage number of conjugated drug molecules (n) per antibody molecule:2.8.

Example 31 Antibody-Drug Conjugate (29)

Process 1: Antibody-Drug Conjugate (29)

Reduction of the antibody: The anti-CD70 antibody produced in ReferenceExample 5 was prepared to have antibody concentration of 10 mg/mL withPBS6.0/EDTA by using the Common procedure B (as absorption coefficientat 280 nm, 1.69 mLmg⁻¹ cm⁻¹ was used) and Common procedure C-1 describedin Production method 1. The solution (1.0 mL) was collected into a 2 mLtube and charged with an aqueous solution of 10 mM TCEP (Tokyo ChemicalIndustry Co., Ltd.) (0.0297 mL; 4.6 equivalents per antibody molecule)and an aqueous solution of 1 M dipotassium hydrogen phosphate (NacalaiTesque, Inc.; 0.050 mL). After confirming that the solution had pH of7.4±0.1, the disulfide bond at hinge part in the antibody was reduced byincubating at 37° C. for 1 hour.

Conjugation between antibody and drug linker: After incubating the abovesolution at 22° C. for 10 minutes, a dimethyl sulfoxide solution (0.0593mL; 9.2 equivalents per antibody molecule) containing 10 mM of thecompound obtained in Process 4 of Example 20 was added thereto andincubated at 22° C. for 40 minutes for conjugating the drug linker tothe antibody. Next, an aqueous solution (0.0119 mL; 18.4 equivalents perantibody molecule) of 100 mM NAC (Sigma-Aldrich Co. LLC) was addedthereto and incubated at 22° C. for another 20 minutes to terminate thereaction of drug linker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (ABS was used as buffer solution) described inProduction method 1 to yield 6 mL of a solution containing the titledantibody-drug conjugate.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=262400 (estimated calculation value), ε_(A,370)=0 (estimatedcalculation value), ε_(D,280)=5000 (measured average value), andε_(D,370)=19000 (measured average value) were used), the followingcharacteristic values were obtained.

Antibody concentration: 1.18 mg/mL, antibody yield: 7.08 mg (71%), andaverage number of conjugated drug molecules (n) per antibody molecule:5.0.

Example 32 Antibody-Drug Conjugate (30)

Process 1:N⁶-(tert-butoxycarbonyl)-N²-[(9H-fluoren-9-ylmethoxy)carbonyl]-L-lysylglycylglycyl-L-phenylalanyl-N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]glycinamide

Glycylglycyl-L-phenylalanyl-N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]glycinamide(a free form of the pharmaceutical compound described in WO97/46260;0.300 g, 0.397 mmol) was reacted in the same manner as Process 1 ofExample 20 by usingN^(ε)-(tert-butoxycarbonyl)-N^(α)-[(9H-fluoren-9-ylmethoxy)carbonyl]-L-lysineinstead of 4-tert-butyl N-[(9H-fluoren-9-ylmethoxy)carbonyl]-L-aspartateto yield the titled compound as a yellow solid (0.471 g, 98%).

MS (ESI) m/z: 1204 (M+H)⁺

Process 2:N⁶-(tert-butoxycarbonyl)-L-lysylglycylglycyl-L-phenylalanyl-N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]glycinamide

The compound (0.417 g, 0.391 mmol) obtained in Process 1 above wasreacted in the same manner as Process 2 of Example 20 to yield thetitled compound as a pale yellow solid (0.272 g, 71%).

MS (ESI) m/z: 1062 (M+H)⁺

Process 3:N⁶-(tert-butoxycarbonyl)-N²-[6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanoyl]-L-lysylglycylglycyl-L-phenylalanyl-N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]glycinamide

The compound (0.210 g, 0.213 mmol) obtained in Process 2 above wasreacted in the same manner as Process 3 of Example 20 to yield thetitled compound as a pale yellow solid (63.0 mg, 21%).

MS (ESI) m/z: 1175 (M+H)⁺

Process 4:N²-[6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanoyl]-L-lysylglycylglycyl-L-phenylalanyl-N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolidino[1,2-b]quinolin-1-yl]glycineamidetrifluoroacetate

Under ice cooling, to the compound (63.0 mg, 53.6 μmol) obtained inProcess 3 above, trifluoroacetic acid (2.00 mL) was added and stirred atroom temperature for 1 hour. The solvent was removed under reducedpressure to yield the titled compound as a yellow solid (50.0 mg, 78%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.89 (3H, t, J=7.2 Hz), 1.13-1.39 (4H, m),1.43-1.58 (7H, m), 1.61-1.73 (1H, m), 1.80-1.94 (2H, m), 2.07-2.28 (4H,m), 2.43 (3H, s), 2.72-2.84 (4H, m), 3.00 (1H, dd, J=13.7, 3.9 Hz), 3.20(2H, brs), 3.55-3.80 (6H, m), 4.20-4.30 (1H, m), 4.42-4.52 (1H, m), 5.27(2H, dd, J=23.7, 19.8 Hz), 5.43 (2H, dd, J=21.9, 16.4 Hz), 5.55-5.65(1H, m), 6.56 (1H, s), 7.02 (2H, s), 7.15-7.27 (5H, m), 7.34 (1H, s),7.64 (3H, brs), 7.83 (1H, d, J=10.6 Hz), 7.98-8.04 (2H, m), 8.09-8.20(2H, m), 8.37 (1H, t, J=5.5 Hz), 8.47 (1H, d, J=8.6 Hz).

MS (ESI) m/z: 1075 (M+H)⁺

Process 5: Antibody-Drug Conjugate (30)

By using the M30-H1-L4P antibody produced in Reference Example 2 and thecompound obtained in Process 4, the titled antibody-drug conjugate wasobtained in the same manner as Process 1 of Example 4.

Antibody concentration: 12.04 mg/mL, antibody yield: 8.4 mg (67%), andaverage number of conjugated drug molecules (n) per antibody molecule:3.2.

Example 33 Antibody-Drug Conjugate (31)

Process 1: Antibody-Drug Conjugate (31)

By using the M30-H1-L4P antibody produced in Reference Example 2 and thecompound obtained in Process 4 of Example 32, the titled antibody-drugconjugate was obtained in the same manner as Process 1 of Example 5.

Antibody concentration: 1.79 mg/mL, antibody yield: 10.74 mg (86%), andaverage number of conjugated drug molecules (n) per antibody molecule:5.1.

Example 34 Antibody-Drug Conjugate (32)

Process 1: Antibody-Drug Conjugate (32)

By using the M30-H1-L4P antibody produced in Reference Example 2 and thecompound obtained in Process 4 of Example 32, the titled antibody-drugconjugate was obtained in the same manner as Process 1 of Example 6.

Antibody concentration: 1.87 mg/mL, antibody yield: 11.22 mg (90%), andaverage number of conjugated drug molecules (n) per antibody molecule:7.0.

Example 35 Antibody-Drug Conjugate (33)

Almost the whole amounts of the antibody-drug conjugates of Examples 33and 34 were mixed and the solution was concentrated by the Commonprocedure A described in Production method 1 to yield the titledantibody-drug conjugate.

Antibody concentration: 10.0 mg/mL, antibody yield: 22.21 mg, andaverage number of conjugated drug molecules (n) per antibody molecule:5.9.

Example 36N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]glycinamide

Process 1:tert-Butyl(2-{[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]amino}-2-oxoethyl)carbamate

To a dichloromethane (3.00 mL) solution ofN-(tert-butoxycarbonyl)-glycine (0.395 g, 2.26 mmol),N-hydroxysuccinimide (0.260 g, 2.26 mmol) and1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (0.433 mg,2.26 mmol) were added and stirred at room temperature for 1 hour. Thissolution was added to a solution consisting of methanesulfonate of thecompound (4) (1.00 g, 1.88 mmol), triethylamine (0.315 mL, 2.26 mmol),and N,N-dimethylformamide (3.00 mL) and stirred at room temperature for16.5 hours. The reaction solution was diluted with chloroform and washedwith 10% citric acid solution, and then the organic layer was dried overanhydrous sodium sulfate. The solvent was removed under reduced pressureand the obtained residues were purified by silica gel columnchromatography [chloroform to chloroform:methanol=9:1 (v/v)] to yieldthe titled compound as a yellow solid (1.16 g, 99%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.86 (3H, t, J=7.2 Hz), 1.30 (9H, s),1.81-1.89 (2H, m), 2.09-2.21 (2H, m), 2.38 (3H, s), 3.15-3.17 (2H, m),3.55-3.56 (2H, m), 5.15 (1H, d, J=18.8 Hz), 5.23 (1H, d, J=19.2 Hz),5.41 (2H, s), 5.55-5.56 (1H, m), 6.53 (1H, s), 6.95 (1H, t, J=5.5 Hz),7.28 (1H, s), 7.77 (1H, d, J=11.0 Hz), 8.39 (1H, d, J=8.6 Hz).

MS (APCI) m/z: 593 (M+H)⁺

Process 2:N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]glycinamide

The compound (0.513 g, 1.01 mmol) obtained in Process 1 above wasreacted in the same manner as Process 4 of Example 17 to yield thetitled compound as a yellow solid (0.463 g, 93%).

¹H-NMR (400 MHz, CD₃OD) δ: 0.96 (3H, t, J=7.0 Hz), 1.89-1.91 (2H, m),2.14-2.16 (1H, m), 2.30 (3H, s), 2.40-2.42 (1H, m), 3.15-3.21 (2H, m),3.79-3.86 (2H, m), 4.63-4.67 (1H, m), 5.00-5.05 (1H, m), 5.23 (1H, d,J=16.0 Hz), 5.48 (1H, d, J=16.0 Hz), 5.62-5.64 (1H, m), 7.40-7.45 (2H,m).

MS (APCI) m/z: 493 (M+H)⁺

Example 37 Antibody-Drug Conjugate (34)

Process 1:N-(tert-butoxycarbonyl)glycylglycyl-L-phenylalanylglycyl-N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]glycinamide

N-(tert-butoxycarbonyl)-glycylglycyl-L-phenylalanylglycine (0.292 mg,0.669 mmol) was dissolved in dichloromethane (5.00 mL), charged withN-hydroxysuccinimide (77.0 mg, 0.0.669 mmol) andN,N′-dicyclohexylcarbodiimide (128 mg, 0.669 mmol), and stirred for 1hour and 20 minutes. The reaction solution was added dropwise to anN,N-dimethylformamide solution (5.00 mL) of the compound (0.275 g, 0.558mmol) of Example 36 and stirred at room temperature for 1 day. Anaqueous solution of 10% citric acid (20.0 mL) was added thereto andextracted with 20 mL of chloroform three times. The obtained organiclayer was evaporated under reduced pressure and the obtained residueswere purified by silica gel column chromatography [chloroform tochloroform:methanol=8:2 (v/v)] to yield the titled compound as a paleyellow solid (0.430 g, 85%).

¹H-NMR (400 MHz, CD₃OD) δ: 0.94 (3H, t, J=7.2 Hz), 1.43 (9H, s),1.83-1.85 (2H, m), 2.20-2.22 (1H, m), 2.29 (3H, s), 2.36-2.39 (2H, m),2.50-2.53 (1H, m), 2.67 (1H, s), 3.08-3.11 (1H, m), 3.18-3.21 (1H, m),3.63-3.67 (4H, m), 3.78-3.82 (1H, m), 3.99 (2H, dd, J=23.5, 16.8 Hz),4.16 (1H, s), 4.58 (1H, d, J=18.8 Hz), 5.15 (1H, d, J=19.2 Hz), 5.25(1H, d, J=16.4 Hz), 5.52 (1H, d, J=16.4 Hz), 5.59-5.61 (1H, m), 6.89(2H, d, J=6.7 Hz), 7.15-7.17 (3H, m), 7.28 (1H, d, J=10.6 Hz), 7.41 (1H,s).

MS (APCI) m/z: 911 (M+H)⁺

Process 2:Glycylglycyl-L-phenylalanylglycyl-N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]glycinamide

The compound (0.227 g, 0.249 mmol) obtained in Process 1 above wasdissolved in dichloromethane (1.00 mL). Trifluoroacetic acid (3.00 mL)was added thereto and stirred for 1 hour. The solvent was removed underreduced pressure and the obtained residues were purified by silica gelcolumn chromatography [chloroform to partitioned organic layer ofchloroform:methanol:water=7:3:1 (v/v/v)] to yield the titled compound asa pale yellow solid (0.200 g, 99%).

¹H-NMR (400 MHz, CD₃OD) δ: 0.93 (3H, t, J=7.4 Hz), 1.85 (2H, q, J=7.3Hz), 2.24-2.45 (5H, m), 2.32 (3H, s), 2.56 (1H, dd, J=13.7, 5.5 Hz),3.09-3.25 (2H, m), 3.66-3.76 (6H, m), 4.18-4.24 (1H, m), 4.76 (1H, d,J=19.2 Hz), 5.18 (1H, d, J=18.8 Hz), 5.30 (1H, t, J=18.4 Hz), 5.52 (1H,d, J=16.0 Hz), 5.63 (1H, t, J=5.9 Hz), 6.93 (2H, d, J=6.6 Hz), 7.17 (3H,q, J=7.3 Hz), 7.30 (1H, d, J=10.9 Hz), 7.42 (1H, s).

MS (APCI) m/z: 811 (M+H)⁺

Process 3:N-[6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanoyl]glycylglycyl-L-phenylalanylglycyl-N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]glycinamide

The compound (0.125 g, 0.154 mmol) obtained in Process 2 above wasreacted in the same manner as Process 3 of Example 20 to yield thetitled compound as a pale yellow solid (0.0775 g, 50%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.86 (3H, t, J=7.2 Hz), 1.18-1.19 (2H, m),1.45-1.48 (4H, m), 1.83-1.85 (2H, m), 2.12-2.17 (4H, m), 2.39 (3H, s),2.68 (1H, dd, J=24.4, 14.7 Hz), 2.83-2.87 (1H, m), 3.17-3.78 (12H, m),4.42-4.45 (1H, m), 5.23 (2H, s), 5.41 (2H, s), 5.58-5.60 (1H, m), 6.53(1H, s), 6.99 (2H, s), 7.15-7.29 (6H, m), 7.76 (1H, d, J=10.9 Hz),7.97-8.00 (1H, m), 8.09-8.12 (3H, m), 8.25-8.28 (1H, m), 8.44 (1H, d,J=8.2 Hz).

MS (APCI) m/z: 1004 (M+H)⁺

Process 4: Antibody-Drug Conjugate (34)

Reduction of the antibody: The M30-H1-L4P antibody produced in ReferenceExample 2 was prepared to have antibody concentration of 10 mg/mL byreplacing the medium with PBS6.0/EDTA by using the Common procedure C-1and Common procedure B (as absorption coefficient at 280 nm, 1.61 mLmg⁻¹cm⁻¹ was used) described in Production method 1. The solution (1.25 mL)was added to a 1.5 mL polypropylene tube and charged with an aqueoussolution of 10 mM TCEP (Tokyo Chemical Industry Co., Ltd.) (0.025 mL;3.0 equivalents per antibody molecule) and an aqueous solution of 1 Mdipotassium hydrogen phosphate (Nacalai Tesque, Inc.; 0.0625 mL). Afterconfirming that the solution had pH of 7.4±0.1, the disulfide bond athinge part in the antibody was reduced by incubating at 37° C. for 1hour.

Conjugation between antibody and drug linker: After adding dimethylsulfoxide (Sigma-Aldrich Co. LLC; 0.102 mL) and a dimethyl sulfoxidesolution (0.047 mL; 5.5 equivalents per antibody molecule) containing 10mM of the compound obtained in above Process 3 to the above solution atroom temperature, it was stirred by using a tube rotator (MTR-103,manufactured by AS ONE Corporation) at room temperature for 40 minutesfor conjugating the drug linker to the antibody. Next, an aqueoussolution (0.009 mL) of 100 mM NAC (Sigma-Aldrich Co. LLC) was addedthereto and stirred at room temperature for another 20 minutes toterminate the reaction of drug linker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (ABS was used as buffer solution) described inProduction method 1 to yield 6 mL of a solution containing the titledantibody-drug conjugate. After that, the solution was concentrated bythe Common procedure A described in Production method 1.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=235300 (calculation value), ε_(A,370)=0 (calculation value),ε_(D,280)=5000 (measured average value), and ε_(D,370)=19000 (measuredaverage value) were used), the following characteristic values wereobtained.

Antibody concentration: 12.4 mg/mL, antibody yield: 8.7 mg (70%), andaverage number of conjugated drug molecules (n) per antibody molecule:3.1.

Example 38 Antibody-Drug Conjugate (35)

Process 1:N-(tert-butoxycarbonyl)glycyl-N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]glycinamide

Methanesulfonate of the compound (4) (0.800 g, 1.51 mmol) was reacted inthe same manner as Process 1 of Example 1 by usingN-(tert-butoxycarbonyl)-glycylglycine (0.419 g, 1.81 mmol) instead of4-(tert-butoxycarbonylamino)butanoic acid to yield the titled compoundas a yellow solid (0.965 g, 99%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.87 (3H, t, J=7.4 Hz), 1.23 (9H, s),1.82-1.89 (2H, m), 2.11-2.19 (2H, m), 2.40 (3H, s), 3.16-3.17 (2H, m),3.52 (2H, ddd, J=21.3, 15.5, 4.7 Hz), 3.77 (2H, ddd, J=24.3, 16.8, 5.9Hz), 5.23 (2H, s), 5.43 (2H, s), 5.56-5.60 (1H, m), 6.53 (1H, s), 7.04(1H, t, J=5.9 Hz), 7.31 (1H, s), 7.80 (1H, d, J=11.0 Hz), 8.12 (1H, t,J=5.5 Hz), 8.31 (1H, d, J=8.6 Hz).

MS (APCI) m/z: 650 (M+H)⁺

Process 2:Glycyl-N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]glycineamidetrifluoroacetate

The compound (0.884 g, 1.36 mmol) obtained in Process 1 above wasreacted in the same manner as Process 2 of Example 1 to yield the titledcompound as a yellow solid (0.787 g, quantitative).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.87 (3H, t, J=7.2 Hz), 1.82-1.89 (2H, m),2.11-2.18 (2H, m), 2.41 (3H, s), 3.17-3.18 (2H, m), 3.63 (2H, s), 3.88(2H, d, J=5.5 Hz), 5.19 (1H, d, J=18.8 Hz), 5.25 (1H, d, J=19.2 Hz),5.42 (2H, s), 5.56-5.61 (1H, m), 6.56 (1H, s), 7.32 (1H, s), 7.81 (1H,d, J=11.0 Hz), 8.01 (3H, brs), 8.65 (1H, d, J=8.6 Hz), 8.72 (1H, t,J=5.5 Hz).

MS (APCI) m/z: 550 (M+H)⁺

Process 3:N-(tert-butoxycarbonyl)glycylglycylphenylalanylglycylglycyl-N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]glycinamide

The compound (0.400 g, 0.728 mmol) obtained in Process 2 above wasreacted in the same manner as Process 1 of Example 1 by usingN-(tert-butoxycarbonyl)-glycylglycyl-L-phenylalanylglycine (0.381 mg,0.873 mmol) instead of 4-(tert-butoxycarbonylamino)butanoic acid toyield the titled compound as a pale yellow solid (0.545 g, 77%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.87 (3H, t, J=7.2 Hz), 1.37 (9H, s),1.80-1.90 (2H, m), 2.09-2.11 (1H, m), 2.18-2.21 (1H, m), 2.40 (3H, s),2.72-2.77 (1H, m), 3.01 (1H, dd, J=13.7, 4.3 Hz), 3.16-3.17 (2H, m),3.52-3.83 (10H, m), 4.48-4.51 (1H, m), 5.21 (1H, d, J=19.2 Hz), 5.26(1H, d, J=18.8 Hz), 5.43 (2H, s), 5.55-5.59 (1H, m), 6.53 (1H, s), 6.99(1H, t, J=5.9 Hz), 7.18-7.24 (5H, m), 7.31 (1H, s), 7.80 (1H, d, J=11.0Hz), 7.90 (1H, t, J=5.3 Hz), 8.02 (1H, t, J=5.5 Hz), 8.15-8.19 (2H, m),8.30 (1H, t, J=5.5 Hz), 8.43 (1H, d, J=8.6 Hz).

MS (APCI) m/z: 968 (M+H)⁺

Process 4:Glycylglycylphenylalanylglycylglycyl-N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolidino[1,2-b]quinolin-1-yl]glycineamidetrifluoroacetate

The compound (0.429 g, 0.443 mmol) obtained in Process 3 above wasreacted in the same manner as Process 2 of Example 1 to yield the titledcompound as a yellow solid (0.385 g, quantitative).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.87 (3H, t, J=7.4 Hz), 1.82-1.89 (2H, m),2.11-2.19 (2H, m), 2.40 (3H, s), 2.74 (1H, dd, J=13.7, 9.8 Hz), 3.03(1H, dd, J=13.7, 4.3 Hz), 3.16-3.18 (2H, m), 3.57-3.58 (2H, m),3.67-3.76 (7H, m), 3.82-3.90 (1H, m), 4.53-4.56 (1H, m), 5.23 (2H, s),5.43 (2H, s), 5.55-5.59 (1H, m), 6.55 (1H, s), 7.17-7.19 (1H, m),7.22-7.29 (4H, m), 7.31 (1H, s), 7.80 (1H, d, J=10.9 Hz), 8.00 (3H,brs), 8.07 (1H, t, J=5.7 Hz), 8.22 (1H, t, J=5.7 Hz), 8.36 (2H, dd,J=10.9, 7.0 Hz), 8.47-8.52 (2H, m).

MS (APCI) m/z: 868 (M+H)⁺

Process 5:N-[6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanoyl]glycylglycylphenylalanylglycylglycyl-N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]glycinamide

The compound (0.278 g, 0.320 mmol) obtained in Process 4 above wasreacted in the same manner as Process 3 of Example 20 to yield thetitled compound as a pale yellow solid (0.166 g, 49%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.87 (3H, t, J=7.2 Hz), 1.14-1.22 (2H, m),1.44-1.49 (4H, m), 1.80-1.90 (2H, m), 2.06-2.13 (3H, m), 2.20 (1H, d,J=14.1 Hz), 2.40 (3H, s), 2.77 (1H, dd, J=13.3, 8.7 Hz), 3.01 (1H, dd,J=13.3, 4.3 Hz), 3.17 (2H, t, J=6.7 Hz), 3.35-3.38 (2H, m), 3.56-3.84(10H, m), 4.48 (1H, dd, J=13.1, 9.2 Hz), 5.23 (2H, s), 5.43 (2H, s),5.55-5.59 (1H, m), 6.53 (1H, s), 6.99 (2H, s), 7.20-7.24 (5H, m), 7.31(1H, s), 7.80 (1H, d, J=11.0 Hz), 8.00 (2H, q, J=5.5 Hz), 8.06 (1H, t,J=5.9 Hz), 8.13 (1H, d, J=8.2 Hz), 8.18 (1H, t, J=5.7 Hz), 8.28 (1H, t,J=5.7 Hz), 8.43 (1H, d, J=8.6 Hz).

MS (APCI) m/z: 1061 (M+H)⁺

Process 6: Antibody-Drug Conjugate (35)

By using the M30-H1-L4P antibody produced in Reference Example 2 and thecompound obtained in Process 5 above, the titled antibody-drug conjugatewas yielded in the same manner as Process 7 of Example 16.

Antibody concentration: 11.7 mg/mL, antibody yield: 8.2 mg (66%), andaverage number of conjugated drug molecules (n) per antibody molecule:3.5.

Example 39 Antibody-Drug Conjugate (36)

Process 1:N-[6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanoyl]glycylglycyl-L-phenylalanylglycyl-N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]glycinamide

Glycylglycyl-L-phenylalanyl-N-[(1S,9S)-9-ethyl-5-fluoro-9-hydroxy-4-methyl-10,13-dioxo-2,3,9,10,13,15-hexahydro-1H,12H-benzo[de]pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-1-yl]glycinamide(a free form of the pharmaceutical compound described in WO97/46260;0.150 g, 0.200 mol) was reacted in the same manner as Process 3 ofExample 20 to yield the titled compound as a pale yellow solid (70.0 mg,37%).

¹H-NMR (400 MHz, DMSO-d₆) δ: 0.87 (3H, t, J=7.4 Hz), 1.15-1.21 (2H, m),1.41-1.50 (4H, m), 1.80-1.90 (2H, m), 2.07-2.12 (4H, m), 2.17-2.23 (1H,m), 2.35-2.40 (1H, m), 2.41 (3H, s), 2.73-2.81 (1H, m), 2.98 (1H, dd,J=13.7, 4.6 Hz), 3.15-3.20 (2H, m), 3.53 (1H, dd, J=16.6, 5.7 Hz),3.62-3.77 (5H, m), 4.39-4.45 (1H, m), 5.22 (1H, d, J=18.9 Hz), 5.27 (1H,d, J=18.9 Hz), 5.39 (1H, d, J=16.0 Hz), 5.44 (1H, d, J=16.0 Hz),5.55-5.60 (1H, m), 6.53 (1H, s), 6.98 (2H, s), 7.13-7.24 (5H, m), 7.32(1H, s), 7.81 (1H, d, J=10.3 Hz), 7.95-8.00 (1H, m), 8.05-8.09 (2H, m),8.28-8.31 (1H, m), 8.41 (1H, d, J=8.6 Hz).

MS (APCI) m/z: 947 (M+H)⁺

Process 2: Antibody-Drug Conjugate (36)

Reduction of the antibody: The M30-H1-L4P antibody produced in ReferenceExample 2 was prepared to have antibody concentration of 10 mg/mL withPBS6.0/EDTA by using the Common procedure B (as absorption coefficientat 280 nm, 1.61 mLmg⁻¹ cm⁻¹ was used) and Common procedure C-1 describedin Production method 1. The solution (1.0 mL) was collected into a 1.5mL tube and charged with an aqueous solution of 10 mM TCEP (TokyoChemical Industry Co., Ltd.) (0.0147 mL; 2.3 equivalents per antibodymolecule) and an aqueous solution of 1 M dipotassium hydrogen phosphate(Nacalai Tesque, Inc.; 0.050 mL). After confirming that the solution hadpH of 7.4±0.1, the disulfide bond at hinge part in the antibody wasreduced by incubating at 37° C. for 1 hour.

Conjugation between antibody and drug linker: After incubating the abovesolution at 22° C. for 10 minutes, a dimethyl sulfoxide solution (0.0295mL; 4.6 equivalents per antibody molecule) containing 10 mM of thecompound obtained in Process 1 was added thereto and incubated at 22° C.for 40 minutes for conjugating the drug linker to the antibody. Next, anaqueous solution (0.00590 mL; 9.2 equivalents per antibody molecule) of100 mM NAC (Sigma-Aldrich Co. LLC) was added thereto and incubated at22° C. for another 20 minutes to terminate the reaction of drug linker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (PBS7.4 was used as buffer solution) described inProduction method 1 to yield 6 mL of a solution containing the titledantibody-drug conjugate.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=235300 (calculation value), ε_(A,370)=0 (calculation value),ε_(D,280)=5000 (measured average value), and ε_(D,370)=19000 (measuredaverage value) were used), the following characteristic values wereobtained.

Antibody concentration: 1.23 mg/mL, antibody yield: 7.38 mg (74%), andaverage number of conjugated drug molecules (n) per antibody molecule:2.0.

Example 40 Antibody-Drug Conjugate (37)

Process 1: Antibody-Drug Conjugate (37)

Reduction of the antibody: The M30-H1-L4P antibody produced in ReferenceExample 2 was prepared to have antibody concentration of 10 mg/mL withPBS6.0/EDTA by using the Common procedure B (as absorption coefficientat 280 nm, 1.61 mLmg⁻¹ cm⁻¹ was used) and Common procedure C-1 describedin Production method 1. The solution (1.0 mL) was collected into a 1.5mL tube and charged with an aqueous solution of 10 mM TCEP (TokyoChemical Industry Co., Ltd.) (0.0295 mL; 4.6 equivalents per antibodymolecule) and an aqueous solution of 1 M dipotassium hydrogen phosphate(Nacalai Tesque, Inc.; 0.050 mL). After confirming that the solution hadpH of 7.4±0.1, the disulfide bond at hinge part in the antibody wasreduced by incubating at 37° C. for 1 hour.

Conjugation between antibody and drug linker: After incubating the abovesolution at 22° C. for 10 minutes, a dimethyl sulfoxide solution (0.0590mL; 9.2 equivalents per antibody molecule) containing 10 mM of thecompound obtained in Process 1 of Example 39 was added thereto andincubated at 22° C. for 40 minutes for conjugating the drug linker tothe antibody. Next, an aqueous solution (0.0118 mL; 18.4 equivalents perantibody molecule) of 100 mM NAC (Sigma-Aldrich Co. LLC) was addedthereto and incubated at 22° C. for another 20 minutes to terminate thereaction of drug linker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (PBS7.4 was used as buffer solution) described inProduction method 1 to yield 6 mL of a solution containing the titledantibody-drug conjugate.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=235300 (calculation value), ε_(A,370)=0 (calculation value),ε_(D,280)=5000 (measured average value), and ε_(D,370)=19000 (measuredaverage value) were used), the following characteristic values wereobtained.

Antibody concentration: 1.22 mg/mL, antibody yield: 7.32 mg (73%), andaverage number of conjugated drug molecules (n) per antibody molecule:2.7.

Example 41 Antibody-Drug Conjugate (38)

Process 1: Antibody-Drug Conjugate (38)

Reduction of the antibody: The M30-H1-L4 antibody produced in ReferenceExample 1 was prepared to have antibody concentration of 10 mg/mL withPBS6.0/EDTA by using the Common procedure B (as absorption coefficientat 280 nm, 1.61 mLmg⁻¹ cm⁻¹ was used) and Common procedure C-1 describedin Production method 1. The solution (1.0 mL) was collected into a 1.5mL tube and charged with an aqueous solution of 10 mM TCEP (TokyoChemical Industry Co., Ltd.) (0.0147 mL; 2.3 equivalents per antibodymolecule) and an aqueous solution of 1 M dipotassium hydrogen phosphate(Nacalai Tesque, Inc.; 0.050 mL). After confirming that the solution hadpH of 7.4±0.1, the disulfide bond at hinge part in the antibody wasreduced by incubating at 37° C. for 1 hour.

Conjugation between antibody and drug linker: After incubating the abovesolution at 22° C. for 10 minutes, a dimethyl sulfoxide solution (0.0295mL; 4.6 equivalents per antibody molecule) containing 10 mM of thecompound obtained in Process 1 of Example 39 was added thereto andincubated at 22° C. for 40 minutes for conjugating the drug linker tothe antibody. Next, an aqueous solution (0.00590 mL; 9.2 equivalents perantibody molecule) of 100 mM NAC (Sigma-Aldrich Co. LLC) was addedthereto and incubated at 22° C. for another 20 minutes to terminate thereaction of drug linker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (PBS7.4 was used as buffer solution) described inProduction method 1 to yield 6 mL of a solution containing the titledantibody-drug conjugate.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=235300 (calculation value), ε_(A,370)=0 (calculation value),ε_(D,280)=5000 (measured average value), and ε_(D,370)=19000 (measuredaverage value) were used), the following characteristic values wereobtained.

Antibody concentration: 1.11 mg/mL, antibody yield: 6.66 mg (67%), andaverage number of conjugated drug molecules (n) per antibody molecule:1.8.

Example 42 Antibody-Drug Conjugate (39)

Process 1: Antibody-Drug Conjugate (39)

Reduction of the antibody: The M30-H1-L4 antibody produced in ReferenceExample 1 was prepared to have antibody concentration of 10 mg/mL withPBS6.0/EDTA by using the Common procedure B (as absorption coefficientat 280 nm, 1.61 mLmg⁻¹ cm⁻¹ was used) and Common procedure C-1 describedin Production method 1. The solution (1.0 mL) was collected into a 1.5mL tube and charged with an aqueous solution of 10 mM TCEP (TokyoChemical Industry Co., Ltd.) (0.0295 mL; 4.6 equivalents per antibodymolecule) and an aqueous solution of 1 M dipotassium hydrogen phosphate(Nacalai Tesque, Inc.; 0.050 mL). After confirming that the solution hadpH of 7.4±0.1, the disulfide bond at hinge part in the antibody wasreduced by incubating at 37° C. for 1 hour.

Conjugation between antibody and drug linker: After incubating the abovesolution at 22° C. for 10 minutes, a dimethyl sulfoxide solution (0.0590mL; 9.2 equivalents per antibody molecule) containing 10 mM of thecompound obtained in Process 1 of Example 39 was added thereto andincubated at 22° C. for 40 minutes for conjugating the drug linker tothe antibody. Next, an aqueous solution (0.0118 mL; 18.4 equivalents perantibody molecule) of 100 mM NAC (Sigma-Aldrich Co. LLC) was addedthereto and incubated at 22° C. for another 20 minutes to terminate thereaction of drug linker.

Purification: The above solution was subjected to purification using theCommon procedure D-1 (PBS7.4 was used as buffer solution) described inProduction method 1 to yield 6 mL of a solution containing the titledantibody-drug conjugate.

Physicochemical characterization: By using the Common procedure Edescribed in Production method 1 (as molar absorption coefficient,ε_(A,280)=235300 (calculation value), ε_(A,370)=0 (calculation value),ε_(D,280)=5000 (measured average value), and ε_(D,370)=19000 (measuredaverage value) were used), the following characteristics values wereobtained.

Antibody concentration: 1.00 mg/mL, antibody yield: 6.00 mg (60%), andaverage number of conjugated drug molecules (n) per antibody molecule:3.4.

Test Example 1 Production of Full-Length Human B7-H3 Variant 1Expression Vector

cDNA encoding human B7-H3 variant 1 was amplified by PCR reaction usingcDNA synthesized from LNCaP cell (American Type Culture Collection:ATCC) total RNA as a template and the following primer set:

primer 1:

5′-ctatagggagacccaagctggctagcatgctgcgtcggcggggcag-3′ (SEQ ID NO: 22) and

primer 2:

5′-aacgggccctctagactcgagcggccgctcaggctatttcttgtccatcatcttctttgctgtcag-3′ (SEQ ID NO: 23).

Next, the obtained PCR product was purified by using MagExtractor PCR &Gel cleanup (Toyobo Co., Ltd.). The purified product was furtherdigested with restriction enzymes (NheI/NotI) and thereafter purified byusing MagExtractor PCR & Gel cleanup (Toyobo Co., Ltd.). pcDNA3.1 (+)plasmid DNA (Life Technologies) was digested with the same restrictionenzymes as above (NheI/NotI) and thereafter purified by usingMagExtractor PCR & Gel cleanup (Toyobo Co., Ltd.).

These purified DNA solutions were mixed, further charged with Ligationhigh (Toyobo Co., Ltd.), and incubated at 16° C. for 8 hours forligation.

Escherichia coli DH5α competent cells (Life Technologies) weretransformed by the addition of the obtained reaction product.

The colonies thus obtained were subjected to colony direct PCR using PCRprimers and BGH reverse primer to select candidate clones.

The obtained candidate clones were cultured in a liquid medium (LB/Amp),and plasmid DNA was extracted with MagExtractor-Plasmid- (Toyobo Co.,Ltd.).

Each obtained clone was compared with the provided CDS sequence by thesequencing analysis between primer 3 (CMV promoter primer):

5′-cgcaaatgggcggtaggcgtg-3′ (SEQ ID NO: 24) and primer 4 (BGH reverseprimer):

5′-tagaaggcacagtcgagg-3′ (SEQ ID NO: 25) with the obtained plasmid DNAas a template.

After confirming the sequence, the obtained clone was cultured in 200 mLof LB/Amp medium, and plasmid DNA was extracted by using VioGene PlasmidMidi V-100 kit.

The vector was designated as pcDNA3.1-B7-H3. The sequence of an ORF siteof the B7-H3 variant 1 gene cloned in the vector is shown in nucleotidepositions 1 to 1602 of SEQ ID NO: 26 (FIG. 16) in the Sequence Listing.Also, the amino acid sequence of the B7-H3 variant 1 is shown in SEQ IDNO: 1 in the Sequence Listing.

Test Example 2 Preparation of CCRF-CEM Cell Stably Expressing B7-H3Variant 1 Gene

pcDNA3.1-B7-H3 produced in Test Example 1 was transfected into CCRF-CEMcells (ATCC) by electroporation using Nucleofector II (manufactured byLonza Group Ltd.). Then, the cells were further cultured for two nightsin RPMI1640 medium (Life Technologies) containing 10% fetal bovine serum(FBS) (hereinafter, referred to as 10% FBS-RPMI1640) under conditions of37° C. and 5% CO₂.

After the 2-day culture, culture was started in 10% FBS-RPMI1640containing 750 μg/mL G418 (Life Technologies) in order to selectCCRF-CEM cells in which pcDNA3.1-B7-H3 was stably integrated.

After the 1-month culture, cloning was carried out by the limitingdilution method in order to yield a single cell clone. Specifically,cells having resistance to G418 were diluted into 10 cells/mL,inoculated to a 96-well plate at a concentration of 100 μL/well, andcultured, and cells allowed to proliferate were recovered fromindividual wells.

Flow cytometry was used for confirming B7-H3 expression in eachrecovered clone. Specifically, each recovered clone was washed twicewith PBS containing 5% FBS, thereafter suspended by the addition of PBScontaining 5% FBS and 10 μg/mL M30, and left standing at 4° C. for 30minutes. The clone was washed twice with PBS containing 5% FBS,thereafter suspended by the addition of Fluorescein-conjugated goat IgGfraction to mouse IgG (Whole Molecule) (#55493, manufactured by ICNPharmaceuticals, Inc.) diluted 1000-fold with PBS containing 5% FBS, andleft standing at 4° C. for 30 minutes. The clone was washed twice withPBS containing 5% FBS, thereafter resuspended in PBS containing 5% FBS,and detected by using a flow cytometer (FC500: Beckman Coulter, Inc.).

The CCRF-CEM cells stably expressing the B7-H3 variant 1 gene thusobtained by these procedures were designated as CEM_V1_(—)3.1_(—)2cells. The parent line CCRF-CEM cells were used as a cell line lackingB7-H3 expression.

Test Example 3 Cell Growth Inhibition Assay (1) of Antibody-DrugConjugate

The CEM_V1_(—)3.1_(—)2 cells produced in Test Example 2 or CCRF-CEMcells (ATCC) were cultured in RPMI1640 (GIBCO) containing 10% fetalbovine serum (MOREGATE) (hereinafter, referred to as a medium). TheCEM_V1_(—)3.1_(—)2 cells or CCRF-CEM cells were prepared to have aconcentration of 8×10⁴ cells/mL by using a medium, added at aconcentration of 25 μL/well to a 96-well microplate for cell culturecharged with 65 μL/well of a medium, and cultured overnight. On the nextday, the M30-H1-L4 antibody, M30-H1-L4P antibody, and antibody-drugconjugate each diluted into 1000 nM, 200 nM, 40 nM, 8 nM, 1.6 nM, 0.32nM, and 0.064 nM by using a medium were added at a concentration of 10μL/well to the microplate. A medium was added at a concentration of 10μL/well to test substance non-supplemented wells. The cells werecultured under 5% CO₂ at 37° C. for 3 days. After the culture, themicroplate was taken out of the incubator and left standing at roomtemperature for 30 minutes. The culture solution was charged with anequal amount of CellTiter-Glo Luminescent Cell Viability Assay (Promega)and stirred. After the microplate was left standing at room temperaturefor 10 minutes, the amount of light emission was measured by using aplate reader (PerkinElmer). The IC₅₀ value was calculated according tothe following equation:

IC ₅₀(nM)=antilog((50−d)×(LOG₁₀ b−LOG₁₀ a)/(d−c)+LOG₁₀ b)

a: Concentration a of the test substance

b: Concentration b of the test substance

c: Ratio of live cells supplemented with the test substance having theconcentration a

d: Ratio of live cells supplemented with the test substance having theconcentration b

The concentrations a and b establish the relation a>b crossing 50% ratioof live cells.

The survival rate of cells at each concentration was calculatedaccording to the following equation:

Survival rate of cells(%)=a/b×100

a: Average amount of light emission from the test substance-supplementedwells (n=2)

b: Average amount of light emission from the test substancenon-supplemented wells (n=10)

The antibody-drug conjugates (6) and (23) exhibited an anticellulareffect of IC₅₀<0.1 (nM) against the CEM_V1_(—)3.1_(—)2 cells. Theantibody-drug conjugates (3), (33), and (39) exhibited an anticellulareffect of 0.1<IC₅₀<1 (nM) against the cells. The antibody-drugconjugates (13), (14), (15), (16), (17), (20), (30), (35), and (37)exhibited an anticellular effect of 1<IC₅₀<100 (nM) against the cells.On the other hand, none of the antibody-drug conjugates exhibited ananticellular effect against the CCRF-CEM cells (>100 (nM)). Neither ofthe M30-H1-L4 antibody nor the M30-H1-L4P antibody exhibited a cytotoxicactivity against both of the cells (>100 (nM)).

Test Example 4 Cell Growth Inhibition Assay (2) of Antibody-DrugConjugate

Antigen-positive cells SR cells (ATCC) or antigen-negative cells Daudicells (ATCC) were cultured in RPMI1640 (GIBCO) containing 10% fetalbovine serum (MOREGATE) (hereinafter, referred to as a medium). The SRcells or Daudi cells were prepared to have a concentration of 2.8×10⁴cells/mL by using a medium and added at a concentration of 90 μL/well toa 96-well microplate for cell culture. Two hours later, the anti-CD30antibody and antibody-drug conjugates (7), (8), (24), and (25) eachdiluted into 40 nM, 8 nM, 1.6 nM, 320 pM, 64 pM, 12.8 pM, and 2.6 pM byusing a medium were added at a concentration of 10 μL/well to themicroplate. A medium was added at a concentration of 10 μL/well to testsubstance non-supplemented wells. The cells were cultured under 5% CO₂at 37° C. for 3 days. After the culture, the microplate was taken out ofthe incubator and left standing at room temperature for 30 minutes. Theculture solution was charged with an equal amount of CellTiter-GloLuminescent Cell Viability Assay (Promega) and stirred. After themicroplate was left standing at room temperature for 10 minutes, theamount of light emission was measured by using a plate reader(PerkinElmer). The IC₅₀ value was calculated according to the followingequation:

IC ₅₀(nM)=antilog((50−d)×(LOG₁₀ b−LOG₁₀ a)/(d−c)+LOG₁₀ b)

a: Concentration a of the test substance

b: Concentration b of the test substance

c: Ratio of live cells supplemented with the test substance having theconcentration a

d: Ratio of live cells supplemented with the test substance having theconcentration b

The concentrations a and b establish the relation a>b crossing 50% ratioof live cells.

The survival rate of cells at each concentration was calculatedaccording to the following equation:

Survival rate of cells(%)=a/b×100

a: Average amount of light emission from the test substance-supplementedwells (n=2)

b: Average amount of light emission from the test substancenon-supplemented wells (n=12)

The antibody-drug conjugates (7), (8), (24), and (25) exhibited ananticellular effect of IC₅₀<0.01 (nM) against the SR cells. On the otherhand, none of the antibody-drug conjugates exhibited an anticellulareffect against the Daudi cells (>4.0 (nM)). The anti-CD30 antibodyexhibited no anticellular effect against both of the cells (>4.0 (nM)).

Test Example 5 Cell Growth Inhibition Assay (3) of Antibody-DrugConjugate

Antigen-positive cells HL-60 cells (ATCC) or antigen-negative cells Rajicells (ATCC) were cultured in RPMI1640 (GIBCO) containing 10% fetalbovine serum (MOREGATE) (hereinafter, referred to as a medium). TheHL-60 cells or Raji cells were prepared to have a concentration of 8×10⁴cells/mL by using a medium and added at a concentration of 25 μL/well toa 96-well microplate for cell culture containing 65 μL/well of medium.The anti-CD33 antibody and antibody-drug conjugates (9), (10), (26), and(27) each diluted into 1000 nM, 200 nM, 40 nM, 8 nM, 1.6 nM, 0.32 nM,and 0.064 nM by using a medium were added at a concentration of 10μL/well to the microplate. A medium was added at a concentration of 10μL/well to test substance non-supplemented wells. The cells werecultured under 5% CO₂ at 37° C. for 3 days. After the culture, themicroplate was taken out of the incubator and left standing at roomtemperature for 30 minutes. The culture solution was charged with anequal amount of CellTiter-Glo Luminescent Cell Viability Assay (Promega)and stirred. After the microplate was left standing at room temperaturefor 10 minutes, the amount of light emission was measured by using aplate reader (PerkinElmer). The IC₅₀ value was calculated according tothe following equation:

IC ₅₀(nM)=antilog((50−d)×(LOG₁₀ b−LOG₁₀ a)/(d−c)+LOG₁₀ b)

a: Concentration a of the test substance

b: Concentration b of the test substance

c: Ratio of live cells supplemented with the test substance having theconcentration a

d: Ratio of live cells supplemented with the test substance having theconcentration b

The concentrations a and b establish the relation a>b crossing 50% ratioof live cells.

The survival rate of cells at each concentration was calculatedaccording to the following equation:

Survival rate of cells(%)=a/b×100

a: Average amount of light emission from the test substance-supplementedwells (n=2)

b: Average amount of light emission from the test substancenon-supplemented wells (n=5)

The antibody-drug conjugate (10) exhibited a cytotoxic effect of IC₅₀<1(nM) against the HL-60 cells. The antibody-drug conjugates (9), (26),and (27) exhibited an anticellular effect of 1<IC₅₀<100 (nM). On theother hand, all of the antibody-drug conjugates exhibited noanticellular effect against the Raji cells (>100 (nM)). The anti-CD33antibody exhibited no anticellular effect against both of the cells(>100 (nM)).

Test Example 6 Cytotoxicity Test (4) of Antibody-Drug Conjugate

Antigen-positive cells U251 cells (ATCC) or antigen-negative cells MCF-7cells (ATCC) were cultured in RPMI1640 (GIBCO) containing 10% fetalbovine serum (MOREGATE) (hereinafter, referred to as a medium). U251cells and MCF-7 cells were prepared to have a concentration of 2.8×10⁴cells/mL by using a medium and added at a concentration of 90 μL/well toa 96-well microplate for cell culture, and cultured overnight. On thenext day, the anti-CD70 antibody and antibody-drug conjugates (11),(12), (28), and (29) each diluted into 1000 nM, 200 nM, 40 nM, 8 nM, 1.6nM, 0.32 nM, and 0.064 nM by using a medium were added at aconcentration of 10 μL/well to the microplate. A medium was added at aconcentration of 10 μL/well to test substance non-supplemented wells.The cells were cultured under 5% CO₂ at 37° C. for 6 days. After theculture, the microplate was taken out of the incubator and left standingat room temperature for 30 minutes. The culture solution was chargedwith an equal amount of CellTiter-Glo Luminescent Cell Viability Assay(Promega) and stirred. After the microplate was left standing at roomtemperature for 10 minutes, the amount of light emission was measured byusing a plate reader (PerkinElmer). The IC₅₀ value was calculatedaccording to the following equation:

IC ₅₀(nM)=antilog((50−d)×(LOG₁₀ b−LOG₁₀ a)/(d−c)+LOG₁₀ b)

a: Concentration a of the test substance

b: Concentration b of the test substance

c: Ratio of live cells supplemented with the test substance having theconcentration a

d: Ratio of live cells supplemented with the test substance having theconcentration b

The concentrations a and b establish the relation a>b crossing 50% ratioof live cells.

The survival rate of cells at each concentration was calculatedaccording to the following equation:

Survival rate of cells(%)=a/b×100

a: Average amount of light emission from the test substance-supplementedwells (n=2)

b: Average amount of light emission from the test substancenon-supplemented wells (n=12)

The antibody-drug conjugate (12) and (29) exhibited a cytotoxic effectof 1<IC₅₀<10 (nM) against the U251 cells. The antibody-drug conjugates(11) and (28) exhibited a cytotoxic effect of 10<IC₅₀<100 (nM). On theother hand, all of the antibody-drug conjugates exhibited no cytotoxiceffect against the MCF-7 cells 90 (nM)). The anti-CD70 antibodyexhibited no cytotoxic effect against both of the cells (>100 (nM)).

Test Example 7 Antitumor Test (1)

Mouse: 5- to 6-week-old female BALB/c nude mice (Charles RiverLaboratories Japan, Inc.) were acclimatized for 4 to 7 days under SPFconditions before use in the experiment. The mice were fed withsterilized solid feed (FR-2, Funabashi Farms Co., Ltd) and givensterilized tap water (prepared by the addition of 5 to 15 ppm sodiumhypochlorite solution).

Assay and calculation expression: In all studies, the major axis andminor axis of tumor were measured twice a week by using an electronicdigital caliper (CD-15C, Mitutoyo Corp.), and the tumor volume (mm³) wascalculated. The calculation expression is as shown below.

Tumor volume(mm³)=½×Major axis(mm)×[Minor axis(mm)]²

All of the antibody-drug conjugates were diluted with physiologicalsaline (Otsuka Pharmaceutical Factory, Inc.) and used at a volume of 10mL/kg for intravenous administration to the tail of each mouse. Humanmelanoma line A375 cells were purchased from ATCC (American Type CultureCollection). 8×10⁶ cells suspended in physiological saline weresubcutaneously transplanted to the right abdomen of each female nudemouse (Day 0), and the mice were randomly grouped at Day 11. TheM30-H1-L4P antibody and antibody-drug conjugate (1), (2), (18), and (19)were each intravenously administered at a dose of 10 mg/kg to the tailof each mouse at Days 11, 18, and 25 in a schedule of qw×3.

The results are shown in FIG. 17. In the drawing, the line with openrhombuses depicts the results about untreated tumor, the line withfilled rhombuses depicts the effect of the M30-H1-L4P antibody, the linewith filled squares depicts the effect of the administered antibody-drugconjugate (1), the line with open squares depicts the effect of theadministered antibody-drug conjugate (2), the line with filled trianglesdepicts the effect of the administered antibody-drug conjugate (18), andthe line with open triangles depicts the effect of the administeredantibody-drug conjugate (19).

The administration of the antibody-drug conjugate (1), (2), (18), or(19) remarkably decreased the tumor volume. Particularly, as a result ofthe administration of the antibody-drug conjugate (2) or (19), the tumorcompletely regressed by Day 18 and was not confirmed to recur even afterDay 39.

In addition, the mice that received the antibody-drug conjugate (1),(2), (18), or (19) were free from notable signs such as weight loss,suggesting that these antibody-drug conjugates are low toxic and highlysafe.

Test Example 8 Antitumor Test (2)

Human melanoma line A375 cells were purchased from ATCC (American TypeCulture Collection). 6×10⁶ cells suspended in physiological saline weresubcutaneously transplanted to the right abdomen of each female nudemouse (Day 0), and the mice were randomly grouped at Day 18. Theantibody-drug conjugate (2) and (19) were each intravenouslyadministered at a dose of 1.3 mg/kg to the tail of each mouse at Days18, 25, and 32 in a schedule of qw×3.

The results are shown in FIG. 18. In the drawing, the line with openrhombuses depicts the results about untreated tumor, the line withfilled squares depicts the effect of the antibody-drug conjugate (2)administered at 1 mg/kg, the line with open squares depicts the effectof the antibody-drug conjugate (2) administered at 3 mg/kg, the linewith filled circles depicts the effect of the antibody-drug conjugate(19) administered at 1 mg/kg, and the line with open circles depicts theeffect of the antibody-drug conjugate (19) administered at 3 mg/kg. Theantibody-drug conjugates (2) and (19) exhibited a tumor growthinhibitory effect in a dose-dependent manner.

Test Example 9 Antitumor Test (3)

Human non-small cell lung cancer line Calu-6 cells were purchased fromATCC (American Type Culture Collection). 5×10⁶ cells suspended inphysiological saline were subcutaneously transplanted to the rightabdomen of each female nude mouse (Day 0), and the mice were randomlygrouped at Day 11. The M30-H1-L4P antibody and antibody-drug conjugate(1), (2), (18), or (19) were each intravenously administered at a doseof 10 mg/kg to the tail of each mouse at Days 11, 18, and 25 in aschedule of qw×3.

The results are shown in FIG. 19. In the drawing, the line with openrhombuses depicts the results about untreated tumor, the line withfilled rhombuses depicts the effect of the M30-H1-L4P antibody, the linewith filled squares depicts the effect of the administered antibody-drugconjugate (1), the line with open squares depicts the effect of theadministered antibody-drug conjugate (2), the line with filled trianglesdepicts the effect of the administered antibody-drug conjugate (18), andthe line with open triangles depicts the effect of the administeredantibody-drug conjugate (19).

The administration of the antibody-drug conjugate (1), (2), (18), or(19) remarkably decreased the tumor volume, and no further tumor growthwas observed after the final administration.

In addition, the mice that received the antibody-drug conjugate (1),(2), (18), or (19) were free from notable signs such as weight loss,suggesting that these antibody-drug conjugates are low toxic and highlysafe.

Test Example 10 Antitumor Test (4)

Human melanoma line A375 cells were purchased from ATCC (American TypeCulture Collection). 8×10⁶ cells suspended in physiological saline weresubcutaneously transplanted to the right abdomen of each female nudemouse (Day 0), and the mice were randomly grouped at Day 14. Theantibody-drug conjugates (3), (20), and (30) were each intravenouslyadministered at each dose (3 and 10 mg/kg) to the tail of each mouse atDay 14 in a schedule of qd×1.

The results are shown in FIG. 20. In the drawing, the line with openrhombuses depicts the results about untreated tumor, the dotted linewith filled squares depicts the effect of the antibody-drug conjugate(3) administered at 3 mg/kg, the solid line with filled squares depictsthe effect of the antibody-drug conjugate (3) administered at 10 mg/kg,the dotted line with filled triangles depicts the effect of theantibody-drug conjugate (20) administered at 3 mg/kg, the solid linewith filled triangles depicts the effect of the antibody-drug conjugate(20) administered at 10 mg/kg, the dotted line with filled circlesdepicts the effect of the antibody-drug conjugate (30) administered at 3mg/kg, and the solid line with filled circles depicts the effect of theantibody-drug conjugate (30) administered at 10 mg/kg.

The administration of the antibody-drug conjugate (3), (20), or (30)remarkably decreased the tumor volume, and all of these antibody-drugconjugates exerted a tumor growth inhibitory effect in a dose-dependentmanner.

In addition, the mice that received the antibody-drug conjugate (3),(20), or (30) were free from notable signs such as weight loss,suggesting that these antibody-drug conjugates are low toxic and highlysafe.

Free Text of Sequence Listing

SEQ ID NO: 1—Amino acid sequence of the B7-H3 variant 1SEQ ID NO: 2—Amino acid sequence of the B7-H3 variant 2SEQ ID NO: 3—Amino acid sequence of CDRH1 of the M30 antibodySEQ ID NO: 4—Amino acid sequence of CDRH2 of the M30 antibodySEQ ID NO: 5—Amino acid sequence of CDRH3 of the M30 antibodySEQ ID NO: 6—Amino acid sequence of CDRL1 of the M30 antibodySEQ ID NO: 7—Amino acid sequence of CDRL2 of the M30 antibodySEQ ID NO: 8—Amino acid sequence of CDRL3 of the M30 antibodySEQ ID NO: 9—Amino acid sequence of the M30-H1-type heavy chainSEQ ID NO: 10—Amino acid sequence of the M30-H2-type heavy chainSEQ ID NO: 11—Amino acid sequence of the M30-H3-type heavy chainSEQ ID NO: 12—Amino acid sequence of the M30-H4-type heavy chainSEQ ID NO: 13—Amino acid sequence of the M30-L1-type light chainSEQ ID NO: 14—Amino acid sequence of the M30-L2-type light chainSEQ ID NO: 15—Amino acid sequence of the M30-L3-type light chainSEQ ID NO: 16—Amino acid sequence of the M30-L4-type light chainSEQ ID NO: 17—Amino acid sequence of the M30-L5-type light chainSEQ ID NO: 18—Amino acid sequence of the M30-L6-type light chainSEQ ID NO: 19—Amino acid sequence of the M30-L7-type light chainSEQ ID NO: 20—Amino acid sequence of a heavy chain of the M30 antibodySEQ ID NO: 21—Amino acid sequence of a light chain of the M30 antibodySEQ ID NO: 22—PCR primer 1SEQ ID NO: 23—PCR primer2SEQ ID NO: 24—CMV promoter primer: primer 3SEQ ID NO: 25—BGH reverse primer: primer 4SEQ ID NO: 26—Nucleotide sequence of the B7-H3 variant 1SEQ ID NO: 27—Amino acid sequence of a heavy chain of the anti-CD30antibodySEQ ID NO: 28—Amino acid sequence of a light chain of the anti-CD30antibodySEQ ID NO: 29—Amino acid sequence of a heavy chain of the anti-CD33antibodySEQ ID NO: 30—Amino acid sequence of a light chain of the anti-CD33antibodySEQ ID NO: 31—Amino acid sequence of a heavy chain of the anti-CD70antibodySEQ ID NO: 32—Amino acid sequence of a light chain of the anti-CD70antibody

1. An antibody-drug conjugate wherein an antitumor compound representedby the following formula:

is conjugated to an antibody via a linker having a structure representedby the following formula: -L¹-L²-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- or-L¹-L²-L^(P)- wherein the antibody is connected to the terminal of L¹,the antitumor compound is connected to the terminal of L^(c) or L^(P),wherein n¹ represents an integer of 0 to 6, L¹ represents-(Succinimid-3-yl-N)—(CH₂)n²-C(═O)—,-(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—,—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—,—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-, or —C(═O)—(CH₂)n⁵-C(═O)—,wherein n² represents an integer of 2 to 8, n³ represents an integer of1 to 8, n⁴ represents an integer of 1 to 8, n⁵ represents an integer of1 to 8, L² represents —NH—(CH₂—CH₂—O)n⁶-CH₂—CH₂—C(═O)—,—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)—, —S—(CH₂)n⁸-C(═O)—, or a singlebond, wherein n⁶ represents an integer of 0 to 6, n⁷ represents aninteger of 1 to 4, n⁸ represents an integer of 1 to 6, L^(P) representsa peptide residue consisting of 3 to 8 amino acids, L^(a) represents—C(═O)—NH—, —NR¹—(CH₂)n⁹-, —O—, or a single bond, wherein n⁹ representsan integer of 1 to 6, R¹ represents a hydrogen atom, an alkyl grouphaving 1 to 6 carbon atoms, —(CH₂)n^(a)-COOH, or —(CH₂)n^(b)-OH, n^(a)represents an integer of 1 to 4, n^(b) represents an integer of 1 to 6,L^(b) represents —CR²(—R³)—, —O—, —NR⁴—, or a single bond, wherein R²and R³ each independently represent a hydrogen atom, an alkyl grouphaving 1 to 6 carbon atoms, —(CH₂)n^(c)-NH₂, —(CH₂)n^(d)-COOH, or—(CH₂)n^(e)-OH, R⁴ represents a hydrogen atom or an alkyl group having 1to 6 carbon atoms, n^(c) represents an integer of 0 to 6, n^(d)represents an integer of 1 to 4, n^(e) represents an integer of 1 to 4,provided that when n^(c) is 0, R² and R³ are not the same as each other,L^(c) represents —CH₂— or —C(═O)—, -(Succinimid-3-yl-N)— has a structurerepresented by the following formula:

which is connected to the antibody at position 3 thereof and isconnected to a methylene group in the linker structure containing thisstructure on the nitrogen atom at position 1, —(N-ly-3-diminiccuS)- hasa structure represented by the following formula:

which is connected to L² at position 3 thereof and is connected to amethylene group in the linker structure containing this structure on thenitrogen atom at position 1, cyc.Hex(1,4) represents a 1,4-cyclohexylenegroup, when L² is —S—(CH₂)n⁸-C(═O)—, L¹ is—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-, provided that any one ortwo or more of linkers of L¹, L², and L^(P) have a structure containinga hydrophilic structure, and said hydrophilic structure means, as forlinker L^(P), the case in which, L^(P) is a peptide residue having ahydrophilic amino acid other than glycine at the N terminal, or L^(P) isa peptide residue in which the C terminal is an oligopeptide consistingof 2 or 3 or more glycines and is connected to the antitumor compound,and even in case that a hydrophilic amino acid is present at N terminal,no other hydrophilic amino acid than glycine is present thereat, or asfor linker L¹, the case in which L¹ is-(succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—, or as for linker L², thecase in which L² is —N[CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)—.
 2. Theantibody-drug conjugate according to claim 1, wherein L¹ is-(Succinimid-3-yl-N)—(CH₂)n²-C(═O)—,-(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—, or—CH₂—C(═O)—NH—(CH₂)n⁴-C(═O)—, wherein n² represents an integer of 2 to8, n³ represents an integer of 1 to 8, n⁴ represents an integer of 1 to8, L² is —NH—(CH₂—CH₂—O)n⁶-CH₂—CH₂—C(═O)—,—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]—CH₂—C(═O)—, or a single bond, wherein n⁶represents an integer of 0 to 6, n⁷ represents an integer of 1 to 4,L^(P) is a peptide residue consisting of 3 to 8 amino acids, each ofL^(a) and L^(b) is a single bond, and L^(c) is —C(═O)—.
 3. Theantibody-drug conjugate according to claim 1, wherein any one of linkersof L¹, L², and L^(P) is the linker containing the hydrophilic structure.4. The antibody-drug conjugate according to claim 3, wherein the linkercontaining the hydrophilic structure is linker L^(P).
 5. Theantibody-drug conjugate according to claim 4, wherein L^(P) is a peptideresidue having a hydrophilic amino acid other than glycine at the Nterminal.
 6. The antibody-drug conjugate according to claim 5, whereinthe hydrophilic amino acid other than glycine is aspartic acid, glutamicacid, lysine, serine, threonine, glutamine, asparagine, histidine,tyrosine, or arginine.
 7. The antibody-drug conjugate according to claim5, wherein the N-terminal hydrophilic amino acid other than glycine inL^(P) is glutamic acid, aspartic acid, or lysine.
 8. The antibody-drugconjugate according to claim 6, wherein the peptide residue followingthe N-terminal hydrophilic amino acid in L^(P) is an amino acid residuecomprising an amino acid selected from phenylalanine, glycine, valine,lysine, citrulline, serine, glutamic acid, and aspartic acid.
 9. Theantibody-drug conjugate according to claim 8, wherein a peptide residuefollowing the N-terminal hydrophilic amino acid in L^(P) is a peptideresidue consisting of 3 or 4 amino acids.
 10. The antibody-drugconjugate according to claim 9, wherein the peptide residue followingthe N-terminal hydrophilic amino acid in L^(P) is GGF or GGFG.
 11. Theantibody-drug conjugate according to claim 10, wherein L^(P) is DGGF,KGGF, EGGF, DGGFG, KGGFG, or EGGFG.
 12. The antibody-drug conjugateaccording to claim 10, wherein L^(P) is DGGFG, KGGFG, or EGGFG.
 13. Theantibody-drug conjugate according to any one of claims 1 to 12, whereinthe linker is a linker having a structure represented by-L¹-L²-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-.
 14. The antibody-drugconjugate according to claim 13, wherein L^(c) is —C(═O)—.
 15. Theantibody-drug conjugate according to claim 14, wherein L¹ is-(Succinimid-3-yl-N)—(CH₂)n²-C(═O)—, n² is an integer of 2 to 5, and L²is a single bond.
 16. The antibody-drug conjugate according to claim 15,wherein n² is
 5. 17. The antibody-drug conjugate according to claim 16,wherein n¹ is 1 to
 3. 18. The antibody-drug conjugate according to claim17, wherein the structure of the —NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- moietyin the linker is —NH—CH₂—C(═O)—, —NH—(CH₂)₂—C(═O)—, —NH—(CH₂)₃—C(═O)—,—NH—CH₂—O—CH₂—C(═O)—, or —NH—(CH₂)₂—O—CH₂—C(═O)—.
 19. The antibody-drugconjugate according to claim 17, wherein the structure of the—NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- moiety in the linker is —NH—CH₂—C(═O)—,—NH—(CH₂)₂—C(═O)—, or —NH—(CH₂)₃—C(═O)—.
 20. The antibody-drug conjugateaccording to any one of claims 1 to 12, wherein the linker is a linkerhaving a structure represented by -L¹-L²-L^(P)-.
 21. The antibody-drugconjugate according to claim 20, wherein L¹ is-(Succinimid-3-yl-N)—(CH₂)n²-C(═O)—, n² is an integer of 2 to 5, and L²is a single bond.
 22. The antibody-drug conjugate according to claim 21,wherein n² is
 5. 23. The antibody-drug conjugate according to claim 4,wherein L^(P) is a peptide residue in which the C terminal is anoligopeptide consisting of 2 or 3 or more glycines and is connected tothe antitumor compound, and even in case that a hydrophilic amino acidis present at N terminal, no other hydrophilic amino acid than glycineis present thereat.
 24. The antibody-drug conjugate according to claim23, wherein the peptide residue consists of 4 to 8 amino acids in thelinker.
 25. The antibody-drug conjugate according to claim 23, whereinthe C-terminal glycine oligopeptide is an oligopeptide consisting of 2or 3 glycines.
 26. The antibody-drug conjugate according to any one ofclaims 23 to 25, wherein the peptide residue of the linker is GGFGG orGGFGGG.
 27. The antibody-drug conjugate according to claim 26, whereinL¹ is -(Succinimid-3-yl-N)—(CH₂)n²-C(═O)— and n² is an integer of 2 to5.
 28. The antibody-drug conjugate according to claim 27, wherein n² is5.
 29. The antibody-drug conjugate according to claim 3, wherein L¹ is-(Succinimid-3-yl-N)—CH[—(CH₂)n³-COOH]—C(═O)—.
 30. The antibody-drugconjugate according to claim 29, wherein n³ is 2 or
 3. 31. Theantibody-drug conjugate according to claim 3, wherein L² is—N[—(CH₂CH₂—O)n⁷-CH₂CH₂—OH]-CH₂—C(═O)—.
 32. The antibody-drug conjugateaccording to claim 31, wherein n⁷ is 2 to
 4. 33. The antibody-drugconjugate according to any one of claims 29 to 32, wherein the linker isa linker having a structure represented by-L¹-L²-L^(P)-NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)-.
 34. The antibody-drugconjugate according to claim 33, wherein L^(c) is —C(═O)—.
 35. Theantibody-drug conjugate according to claim 34, wherein n¹ is 1 to
 3. 36.The antibody-drug conjugate according to claim 35, wherein L^(P) isGGFG.
 37. The antibody-drug conjugate according to claim 36, wherein thestructure of the —NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- moiety in the linker is—NH—CH₂—C(═O)—, —NH—(CH₂)₂—C(═O)—, —NH—(CH₂)₃—C(═O)—,—NH—CH₂—O—CH₂—C(═O)—, or —NH—(CH₂)₂—O—CH₂—C(═O)—.
 38. The antibody-drugconjugate according to claim 36, wherein the structure of the—NH—(CH₂)n¹-L^(a)-L^(b)-L^(c)- moiety in the linker is —NH—CH₂—C(═O)—,—NH—(CH₂)₂—C(═O)—, or —NH—(CH₂)₃—C(═O)—.
 39. The antibody-drug conjugateaccording to claim 1 or 2, wherein the drug-linker structure moiety inthe antibody-drug conjugate has one structure selected from thefollowing drug-linker structure group:-(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂—O—CH₂—C(═O)—(NH-DX),-(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),-(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),-(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF—NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF—NH—CH₂—O—CH₂—C(═O)—(NH-DX),-(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF—NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),-(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),-(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),-(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)—(NH-DX),—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF—NH—CH₂—O—CH₂—C(═O)—(NH-DX),—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),—CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGF—NH—CH₂CH₂CH₂—C(═O)—(NH-DX),—CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGF—NH—CH₂—O—CH₂—C(═O)—(NH-DX),—CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGF—NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),—CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),—CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),—CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)—(NH-DX),—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGF—NH—CH₂—O—CH₂—C(═O)—(NH-DX),—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGF—NH—CH₂CH₂CH₂—C(═O)—(NH-DX),—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGF—NH—CH₂—O—CH₂—C(═O)—(NH-DX),—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGF—NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂CH₂—C(═O)—(NH-DX),—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂—O—CH₂—C(═O)—(NH-DX),—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF—NH—CH₂CH₂CH₂—C(═O)—(NH-DX),—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF—NH—CH₂—O—CH₂—C(═O)—(NH-DX),—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF—NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂CH₂—C(═O)—(NH-DX),—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂—O—CH₂—C(═O)—(NH-DX),—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-NH—CH₂CH₂—O—CH₂—C(═O)—(NH-DX),-(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—(NH-DX),-(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF—(NH-DX),-(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-(NH-DX),-(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-(NH-DX),—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGF—(NH-DX),—CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGF—(NH-DX),—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-DGGFG-(NH-DX),—CH₂—C(═O)—NH—CH₂CH₂—C(═O)—KGGFG-(NH-DX),—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGF—(NH-DX),—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGF—(NH-DX),—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-DGGFG-(NH-DX),—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)—KGGFG-(NH-DX),—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGF—(NH-DX),—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGF—(NH-DX),—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-DGGFG-(NH-DX),—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)—KGGFG-(NH-DX),-(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-GGFGG-(NH-DX),-(Succinimid-3-yl-N)—CH₂CH₂CH₂CH₂CH₂—C(═O)-GGFGGG-(NH-DX),—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-GGFGG-(NH-DX),—CH₂—C(═O)—NH—CH₂CH₂—C(═O)-GGFGGG-(NH-DX),—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-GGFGG-(NH-DX),—C(═O)-cyc.Hex(1,4)-CH₂—(N-ly-3-diminiccuS)-S—CH₂CH₂—C(═O)-GGFGGG-(NH-DX),—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-GGFGG-(NH-DX),—C(═O)—CH₂CH₂CH₂CH₂CH₂CH₂—C(═O)-GGFGGG-(NH-DX) wherein-(Succinimid-3-yl-N)— has a structure represented by the followingformula:

which is connected to the antibody at position 3 thereof and isconnected to a methylene group in the linker structure containing thisstructure on the nitrogen atom at position 1, cyc.Hex(1,4) represents a1,4-cyclohexylene group, —(N-ly-3-diminiccuS)- has a structurerepresented by the following formula:

which is connected to L² at position 3 thereof and is connected to amethylene group in the linker structure containing this structure on thenitrogen atom at position 1, and —(NH-DX) is a group represented by thefollowing formula:

wherein the nitrogen atom of the amino group at position 1 is theconnecting position.
 40. The antibody-drug conjugate according to claim1, wherein an average number of conjugated antitumor compounds perantibody is in a range of from 1 to
 10. 41. The antibody-drug conjugateaccording to claim 1, wherein an average number of conjugated antitumorcompounds per antibody is in a range of from 1 to
 8. 42. Theantibody-drug conjugate according to claim 1, wherein an average numberof conjugated antitumor compounds per antibody is in a range of from 3to
 8. 43. The antibody-drug conjugate according to claim 1, wherein theantibody is an antibody having one or more of a property of recognizinga target cell, a property of binding to a target cell, a property ofinternalizing in a target cell, and a property of damaging a targetcell.
 44. The antibody-drug conjugate according to claim 43, wherein thetarget cell is a tumor cell.
 45. The antibody-drug conjugate accordingto claim 43, wherein the antibody is an anti-A33 antibody, an anti-B7-H3antibody, an anti-CanAg antibody, an anti-CD20 antibody, an anti-CD22antibody, an anti-CD30 antibody, an anti-CD33 antibody, an anti-CD56antibody, an anti-CD70 antibody, an anti-CEA antibody, an anti-Criptoantibody, an anti-EphA2 antibody, an anti-G250 antibody, an anti-MUC1antibody, an anti-GPNMB antibody, an anti-integrin antibody, ananti-PSMA antibody, an anti-tenascin-C antibody, an anti-SLC44A4antibody, or an anti-mesothelin antibody.
 46. The antibody-drugconjugate according to claim 43, wherein the antibody is an anti-B7-H3antibody, an anti-CD30 antibody, an anti-CD33 antibody, or an anti-CD70antibody.
 47. The antibody-drug conjugate according to claim 43, whereinthe antibody is an anti-B7-H3 antibody.
 48. A drug containing theantibody-drug conjugate according to claim 1 or a salt thereof.
 49. Anantitumor drug and/or anticancer drug containing the antibody-drugconjugate according to claim 1 or a salt thereof.
 50. The antitumor drugand/or anticancer drug according to claim 49, which is applied to lungcancer, kidney cancer, urothelial cancer, colorectal cancer, prostatecancer, glioblastoma multiforme, ovarian cancer, pancreatic cancer,breast cancer, melanoma, liver cancer, bladder cancer, stomach cancer,or esophageal cancer.
 51. A pharmaceutical composition containing theantibody-drug conjugate according to claim 1, a salt thereof or ahydrate thereof as an active component, and a pharmaceuticallyacceptable formulation component.
 52. The pharmaceutical compositionaccording to claim 51, which is applied to lung cancer, kidney cancer,urothelial cancer, colorectal cancer, prostate cancer, glioblastomamultiforme, ovarian cancer, pancreatic cancer, breast cancer, melanoma,liver cancer, bladder cancer, stomach cancer, or esophageal cancer. 53.A method for treating tumor and/or cancer comprising administering theantibody-drug conjugate according to claim 1, a salt thereof or ahydrate thereof.
 54. The treatment method according to claim 53, whichis applied to lung cancer, kidney cancer, urothelial cancer, colorectalcancer, prostate cancer, glioblastoma multiforme, ovarian cancer,pancreatic cancer, breast cancer, melanoma, liver cancer, bladdercancer, stomach cancer, or esophageal cancer.